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 A352050 Sum of the 4th powers of the divisor complements of the odd proper divisors of n. 11
 0, 16, 81, 256, 625, 1312, 2401, 4096, 6642, 10016, 14641, 20992, 28561, 38432, 51331, 65536, 83521, 106288, 130321, 160256, 196963, 234272, 279841, 335872, 391250, 456992, 538083, 614912, 707281, 821312, 923521, 1048576, 1200643, 1336352, 1503651, 1700608, 1874161 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA a(n) = n^4 * Sum_{d|n, d=2} k^4 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 14 2023 EXAMPLE a(10) = 10^4 * Sum_{d|10, d<10, d odd} 1 / d^4 = 10^4 * (1/1^4 + 1/5^4) = 10016. MAPLE f:= proc(n) local m, d; m:= n/2^padic:-ordp(n, 2); add((n/d)^4, d = select(`<`, numtheory:-divisors(m), n)) end proc:map(f, [\$1..40]); # Robert Israel, Apr 03 2023 MATHEMATICA A352050[n_]:=DivisorSum[n, 1/#^4&, #

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Last modified September 28 14:43 EDT 2023. Contains 365736 sequences. (Running on oeis4.)