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.
%I A319525 #13 Nov 30 2024 08:50:22 %S A319525 1,2,5,4,11,10,17,8,25,22,23,20,31,34,55,16,41,50,47,44,85,46,59,40, %T A319525 121,62,125,68,67,110,73,32,115,82,187,100,83,94,155,88,97,170,103,92, %U A319525 275,118,109,80,289,242,205,124,127,250,253,136,235,134,137,220 %N A319525 Completely multiplicative with a(prime(k)) = prime(2*k - 1) (where prime(k) denotes the k-th prime). %C A319525 This sequence is a permutation of A066208. %C A319525 See A297002 for a similar sequence. %H A319525 Antti Karttunen, <a href="/A319525/b319525.txt">Table of n, a(n) for n = 1..20000</a> %H A319525 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %F A319525 a(n) = A064989(A297002(n)). %F A319525 a(n) >= n with equality iff n is a power of 2 (A000079). %o A319525 (PARI) a(n) = my (f=factor(n)); prod(i=1, #f~, prime(2*primepi(f[i, 1]) - 1)^f[i, 2]) %Y A319525 Cf. A000079, A066208, A297002. %Y A319525 Cf. also A166651. %K A319525 nonn,mult %O A319525 1,2 %A A319525 _Rémy Sigrist_, Sep 22 2018