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 A339894 #7 Dec 21 2020 23:03:54 %S A339894 0,1,2,1,3,2,4,2,3,3,5,3,6,4,4,2,7,3,8,4,5,5,9,3,4,6,4,5,10,4,11,3,6, %T A339894 7,5,4,12,8,7,4,13,5,14,6,5,9,15,4,6,5,8,7,16,5,6,5,9,10,17,5,18,11,6, %U A339894 3,7,6,19,8,10,6,20,5,21,12,6,9,7,7,22,5,5,13,23,6,8,14,11,6,24,6,8,10,12,15,9,4,25 %N A339894 a(n) = A000523(A122111(n)). %H A339894 Antti Karttunen, <a href="/A339894/b339894.txt">Table of n, a(n) for n = 1..16384</a> %H A339894 Antti Karttunen, <a href="/A339894/a339894.txt">Data supplement: n, a(n) computed for n = 1..65537</a> %H A339894 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %F A339894 a(n) = A000523(A122111(n)). %o A339894 (PARI) %o A339894 A000523(n) = if( n<1, 0, #binary(n) - 1); %o A339894 A122111(n) = if(1==n,n,my(f=factor(n), es=Vecrev(f[,2]),is=concat(apply(primepi,Vecrev(f[,1])),[0]),pri=0,m=1); for(i=1, #es, pri += es[i]; m *= prime(pri)^(is[i]-is[1+i])); (m)); %o A339894 A339894(n) = A000523(A122111(n)); %Y A339894 Cf. A000523, A122111, A339895, A339896. %K A339894 nonn %O A339894 1,3 %A A339894 _Antti Karttunen_, Dec 21 2020