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Partial sums of A157502.
2

%I #10 Oct 28 2019 02:27:26

%S 2,8,16,26,38,52,70,90,112,136,162,190,220,252,286,324,364,406,450,

%T 496,544,594,646,700,756,814,874,936,1002,1070,1140,1212,1286,1362,

%U 1440,1520,1602,1686,1772,1860,1950,2042,2136,2232,2330,2432,2536

%N Partial sums of A157502.

%F Set R(n) = floor(A157502(n)/2) and S(n) = floor(sqrt(A157502(n))/2); then a(n) = R(n)*(R(n) + 1) - (4*S(n)^3 + 6*S(n)^2 + 2*S(n))/3.

%e a(4) = 2 + 6 + 8 + 10 = 26.

%o (PARI) lista(nn) = {s = 0; forstep (i = 2, nn, 2, if (! issquare(i), s+=i; print1(s, ", ");););} \\ _Michel Marcus_, Aug 26 2013

%Y Cf. A157502.

%K nonn

%O 1,1

%A _Gerald Hillier_, Mar 02 2009

%E More terms from _Michel Marcus_, Aug 26 2013