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%I #11 Aug 30 2021 03:12:21
%S 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,32,33,34,35,36,37,38,39,40,41,42,
%T 43,44,45,46,47,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,96,97,
%U 98,99,100,101,102,103,104,105,106,107,108,109,110,111,128,129,130,131,132,133,134,135,136,137,138,139
%N a(n) = n + 2^4 * floor(n/2^4) + 3^4 * floor(n/3^4) + 4^4 * floor(n/4^4) + ...
%C Partial sums of A300909.
%H Seiichi Manyama, <a href="/A309127/b309127.txt">Table of n, a(n) for n = 1..10000</a>
%F G.f.: (1/(1 - x)) * Sum_{k>=1} k^4 * x^(k^4)/(1 - x^(k^4)).
%F a(n) ~ zeta(5/4)*n^(5/4)/5 - n/2. - _Vaclav Kotesovec_, Aug 30 2021
%t Table[Sum[k^4 Floor[n/k^4], {k, 1, n}], {n, 1, 75}]
%t nmax = 75; CoefficientList[Series[1/(1 - x) Sum[k^4 x^(k^4)/(1 - x^(k^4)), {k, 1, Floor[nmax^(1/4)] + 1}], {x, 0, nmax}], x] // Rest
%o (PARI) a(n) = sum(k=1, n, k^4*(n\k^4)); \\ _Seiichi Manyama_, Aug 30 2021
%Y Cf. A013938, A024916, A300909, A309125, A309126.
%K nonn
%O 1,2
%A _Ilya Gutkovskiy_, Jul 13 2019