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Row sums of triangle in A154721.
4

%I #7 Feb 03 2019 17:17:17

%S 0,4,6,16,10,24,28,32,54,60,44,96,52,56,120,96,102,144,76,120,210,176,

%T 138,288,200,156,324,168,174,420,186,320,396,204,350,504,370,380,546,

%U 400,328,756,344,352,900,368,376,672,392,600

%N Row sums of triangle in A154721.

%C a(n) is even for all n.

%H Nathaniel Johnston, <a href="/A154784/b154784.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A154783(n) - n.

%p isnotcomp:=proc(n)return (n=1 or isprime(n)) end:

%p 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

%Y Cf. A154720, A154721, A154723, A154783, A154785, A154786.

%K easy,nonn

%O 1,2

%A _Omar E. Pol_, Jan 15 2009

%E Edited by _Omar E. Pol_, Jan 17 2009

%E a(11)-a(50) from _Nathaniel Johnston_, Apr 19 2011