|
%I #6 Feb 12 2015 04:19:18
%S 6,27,55,356,681,1177,1874,3207,5116,7157,9290,13191,21319,32012,
%T 48525,68046,92647,119624,170925,267286,397439,557280,720481,897142,
%U 1111415,1361736,1637569,1933910,2240091,2629684,3116561,3612090,4154503
%N Partial sums of A034897.
%C Partial sums of hyperperfect numbers. The subsequence of prime values in this partial sum begins: 21319, 92647, 720481.
%F a(n) = SUM[i=1..n] A034897(i) = SUM[i=1..n] {m such that k*sigma(m) = (k+1)*m + k - 1 for some positive integer k, and sigma being the divisor function A000005; noting that k=1 gives perfect numbers}.
%e a(x) = 6 + 21 + 28 + 301 + 325 + 496 + 697 + 1333 + 1909 + 2041 + 2133 + 3901 + 8128 + 10693 + 16513 + 19521 + 24601 = 92647 is prime.
%Y Cf. A034897, A034898, A007592, A019279.
%K nonn
%O 1,1
%A _Jonathan Vos Post_, Mar 12 2010
|
