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 A093051 #12 Sep 14 2024 06:50:13 %S A093051 0,1,4,3,7,5,8,7,12,9,12,11,15,13,16,15,21,17,20,19,23,21,24,23,28,25, %T A093051 28,27,31,29,32,31,38,33,36,35,39,37,40,39,44,41,44,43,47,45,48,47,53, %U A093051 49,52,51,55,53,56,55,60,57,60,59,63,61,64,63,71,65,68,67,71 %N A093051 Exponent of 2 in (3^n-3)*2^n. %F A093051 Recurrence: a(2n) = a(n) + [(n+1)/2] + 1, a(2n+1) = 2n+1. %F A093051 a(n) = A090740(n) + n - 1, for n >= 1. - _Amiram Eldar_, Sep 14 2024 %o A093051 (PARI) a(n)=if(n<1,0,if(n%2==0,a(n/2)+2*floor((n+2)/4)+1,n)) %Y A093051 a(n) is the exponent of 2 in A009613(n), A010043(n), A010046(n), A012388(n-1), A009518(n), A012391(n-1), A012457(n-1), A012458(n-1), A012461(n-1), A012462(n-2). %Y A093051 Cf. A093050, A093052, A090740. %K A093051 nonn %O A093051 0,3 %A A093051 _Ralf Stephan_, Mar 16 2004