cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A337204 Sum of the odd divisors of the primorial inflation of n.

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%I A337204 #8 Aug 28 2020 11:06:52
%S A337204 1,1,4,1,24,4,192,1,13,24,2304,4,32256,192,78,1,580608,13,11612160,24,
%T A337204 624,2304,278691840,4,403,32256,40,192,8360755200,78,267544166400,1,
%U A337204 7488,580608,3224,13,10166678323200,11612160,104832,24,427000489574400,624,18788021541273600,2304,240,278691840,901825033981132800,4,22971,403
%N A337204 Sum of the odd divisors of the primorial inflation of n.
%H A337204 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a>
%H A337204 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A337204 a(n) = A000593(A108951(n)).
%t A337204 Array[DivisorSum[Apply[Times, FactorInteger[#] /. {p_, e_} /; e > 0 :> Apply[Times, Prime@ Range@ PrimePi@ p]^e], # &, OddQ] &, 50] (* _Michael De Vlieger_, Aug 27 2020 *)
%o A337204 (PARI)
%o A337204 A000593(n) = sigma(n>>valuation(n, 2));
%o A337204 A034386(n) = prod(i=1, primepi(n), prime(i));
%o A337204 A108951(n) = { my(f=factor(n)); prod(i=1, #f~, A034386(f[i, 1])^f[i, 2]) }; \\ From A108951
%o A337204 A337204(n) = A000593(A108951(n));
%Y A337204 Row 1 of A337205.
%Y A337204 Cf. A000593, A034386, A108951, A337203.
%Y A337204 Cf. also A322819.
%K A337204 nonn
%O A337204 1,3
%A A337204 _Antti Karttunen_, Aug 22 2020