login
A154786
Row sums of triangle in A154725.
6
0, 0, 0, 8, 10, 12, 14, 32, 36, 40, 44, 72, 52, 56, 90, 64, 102, 144, 38, 120, 168, 132, 138, 240, 200, 156, 270, 168, 174, 360, 124, 320, 396, 136, 350, 432, 296, 380, 546, 320, 328, 672, 344, 352, 810, 368, 376, 672, 294, 600, 816, 520, 530, 864, 660, 784, 1140
OFFSET
1,4
FORMULA
a(n) = A154785(n) - n.
a(n) = A005843(n)*A061357(n). - Omar E. Pol, Jan 20 2009
MAPLE
A154786 := proc(n) local a, d; a := 0 ; for d from 1 to n-2 do if isprime(n-d) and isprime(n+d) then a := a+2*n; fi; od: a ; end: for n from 1 to 80 do printf("%d, ", A154786(n)) ; od: # R. J. Mathar, Jan 18 2009
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Jan 15 2009, Jan 16 2009
EXTENSIONS
Edited by Omar E. Pol, Jan 17 2009
Extended by R. J. Mathar, Jan 18 2009
STATUS
approved