cp's OEIS Frontend

A351252 a(n) = sigma(n) * A276086(n), pointwise product of the sum of divisors function and the primorial base exp-function.

%I A351252 #11 Feb 17 2022 16:04:48
%S A351252 2,9,24,63,108,60,80,225,390,810,1080,700,700,1800,3600,6975,8100,
%T A351252 4875,5000,15750,24000,40500,54000,37500,38750,78750,150000,315000,
%U A351252 337500,504,448,1323,2016,3402,6048,3185,2660,6300,11760,28350,26460,16800,15400,44100,81900,113400,151200,108500,99750,244125,378000
%N A351252 a(n) = sigma(n) * A276086(n), pointwise product of the sum of divisors function and the primorial base exp-function.
%H A351252 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%H A351252 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A351252 a(n) = A000203(n) * A276086(n).
%t A351252 Array[Block[{i = 1, m = 1, n = #, p}, While[n > 0, p = Prime[i]; m *= p^Mod[n, p]; n = Quotient[n, p]; i++]; DivisorSigma[1, #]*m] &, 51] (* _Michael De Vlieger_, Feb 17 2022, after _Jean-François Alcover_ at A276086 *)
%o A351252 (PARI)
%o A351252 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A351252 A351252(n) = (sigma(n) * A276086(n));
%Y A351252 Cf. A000203, A276086.
%Y A351252 Cf. also A324580, A341529, A351458.
%K A351252 nonn
%O A351252 1,1
%A A351252 _Antti Karttunen_, Feb 17 2022