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A154784
Row sums of triangle in A154721.
4
0, 4, 6, 16, 10, 24, 28, 32, 54, 60, 44, 96, 52, 56, 120, 96, 102, 144, 76, 120, 210, 176, 138, 288, 200, 156, 324, 168, 174, 420, 186, 320, 396, 204, 350, 504, 370, 380, 546, 400, 328, 756, 344, 352, 900, 368, 376, 672, 392, 600
OFFSET
1,2
COMMENTS
a(n) is even for all n.
LINKS
FORMULA
a(n) = A154783(n) - n.
MAPLE
isnotcomp:=proc(n)return (n=1 or isprime(n)) end:
for n from 1 to 50 do rsum:=0: for k from 1 to 2*n-1 do if(not k=n and (isnotcomp(k) and isnotcomp(2*n-k)))then rsum:=rsum+k:fi:od: printf("%d, ", rsum):od: # Nathaniel Johnston, Apr 19 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Jan 15 2009
EXTENSIONS
Edited by Omar E. Pol, Jan 17 2009
a(11)-a(50) from Nathaniel Johnston, Apr 19 2011
STATUS
approved