Smarandache Summands

 

Edited by M. Bencze

Sacele, Romania

 

 

 

Let n>k≥1 be two integers.  Then a Smarandache Summand is defined as:

 

S(n, _k) =  ∑ (n-k·i)    [for signed numbers]

              0<|n-k·i|≤n

              i=0, 1, 2, … .

 

S|n, _k| =  ∑ |n-k·i|    [for absolute value numbers]

              0<|n-k·i|≤n

              i=0, 1, 2, … .

 

which are duals and semi-duals respectively of Smarandacheials.

 

S(n, ₁) and S(n, ₂) with corresponding S|n, ₁| and S|n, ₂| are trivial.

 

a)      In the case k=3:

 

S(n, ₃) =  ∑ (n-3i) = n+(n-3)+(n-6)+… ; [for signed numbers].

              0<|n-3i|≤n

              i=0, 1, 2, … .

 

S|n, ₃| =  ∑ |n-3i| = n+|n-3|+|n-6|+… ; [for absolute value numbers].

              0<|n-3i|≤n

              i=0, 1, 2, … .

 

Thus S(7, ₃) = 7+(7-3)+(7-6)+(7-9)+(7-12) = 7+(4)+(1)+(-2)+(-5) = 5; [for signed numbers].

Thus S|7, ₃| = 7+|7-3|+|7-6|+|7-9|+|7-12| = 7+4+1+2+5 = 19; [for absolute value numbers].

 

The sequence is S(n, ₃): 3, 2, 0, 5, 3, 0, 7, 4, 0, 9, 5, 0, … ; [for signed numbers].

The sequence is S|n, ₃|: 7, 12, 18, 19, 27, 36, 37, 48, … ; [for absolute value numbers].

 

4) In the case k=4:

 

S(n, ₄) =  ∑ (n-4i) = n+(n-4)+(n-8)… ; [for signed numbers].

              0<|n-4i|≤n

              i=0, 1, 2, … .

 

S|n, ₄| =  ∑ |n-4i| = n+|n-4|+|n-8|… ; [for absolute value numbers].

              0<|n-4i|≤n

              i=0, 1, 2, … .

 

Thus S(9, ₄) = 9+(9-4)+(9-8)+(9-12)+(9-16) = 9+(5)+(1)+(-3)+(-7) = 5; for signed numbers.

Thus S|9, ₄| = 9+|9-4|+|9-8|+|9-12|+|9-16| = 9+5+1+3+7 = 25; [for absolute value numbers].

 

The sequence is S(n, ₄) =  3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 8, 0, 9, 0, 10, 0, 11, … . 

The sequence is S|n, ₄| = 9, 16, 16, 24, 25, 36, 36, 48, 49, 64, 64, 80, 81, 100, 100, … .

 

5) In the case k=5:

 

S(n, ₅) =  ∑ (n-5i) = n+(n-5)+(n-10)… .

              0<|n-5i|≤n

              i=0, 1, 2, … .

 

S|n, ₅| =  ∑ |n-5i| = n+|n-5|+|n-10|… .

              0<|n-5i|≤n

              i=0, 1, 2, … .

 

Thus S(11, ₅) = 11+(11-5)+(11-10)+(11-15)+(11-20) = 11+6+1+(-4)+(-9) = 5.

Thus S|11, ₅| = 11+|11-5|+|11-10|+|11-15|+|11-20| = 11+6+1+4+9 = 31.

 

The sequence is S(n, ₅): 3, 6, 2, 6, 0, 5, 10, 3, 9, 0, 7, 14, 4, 12, 0, … .   

The sequence is S|n, ₅|: 11, 12, 20, 20, 30, 31, 32, 33, 45, 60, 61, 62, 80, 80, 100, … .

 

 

More general:

Let n>k≥1 be two integers and m≥0 another integer. 

Then the Generalized Smarandache Summand is defined as:

 

S(n, m, _k) =  ∑ (n-k·i)    [for signed numbers].

                         i=0, 1, 2, …, floor[(n+m)/k].

 

S|n, m, _k| =  ∑ |n-k·i|    [for absolute value numbers].

                       i=0, 1, 2, …, floor[(n+m)/k].

 

For examples:

S(7, 9, ₂) = 7+(7-2)+(7-4)+(7-6)+(7-8)+(7-10)+(7-12)+(7-14)+(7-16)

               = 7+(5)+(3)+(1)+(-1)+(-3)+(-5)+(-7)+(-9) = -2.

S|7, 3, ₂| = 7+|7-2|+|7-4|+|7-6|+|7-8|+|7-10| = 7+5+3+1+1+3 = 20.

 

 

References:

J. Dezert, editor, “Smarandacheials”, Mathematics Magazine, Aurora, Canada, No. 4/2004;

http://fs.unm.edu/Smarandacheials.htm.

F. Smarandache, “Back and Forth Factorials”, Arhivele Statului, Filiala Valcea, Rm. Valcea, Romania,  1972;

and Arizona State Univ., Special Collections, 1990.