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 A174837 #3 Jan 20 2014 22:19:35 %S A174837 9,2,45,2,11,2,225,2,11,2,56,2,11,2,1125,2,11,2,56,2,11,281,2,11,2,56, %T A174837 2,11,2,5625 %N A174837 Sequence built as it follows in comments. %C A174837 If we denote "A" the finite sequence between a(2^(n-1)-2) and a(2^n-2), the subsequence of a between %C A174837 a(2^(n)-2) and a(2^(n+1)-2) is given by: " A - a(3*2^(n-1)-2) - A" for every n>=2. %F A174837 a(2n+1)=2. a(2^(n+1)-2)=9*5^n. a(3*2^n-2)=(9*5^n-1)/4. %e A174837 a(4)=a(2*3-2)=(9*4-1)/4=11. a(14)=a(2^4-2)==9*5^3=125*9=1125. %e A174837 Between a(2) and a(6) the subsequence is "2, 11, 2"; then between a(6) and a(14) the subsequence of a is: %e A174837 "2, 11, 2, a(10)=56, 2, 11, 2". %e A174837 It seems that this new sequence gives the number of 2 in the sets of 2 of the sequence A174835. %Y A174837 Cf. A174835. %K A174837 easy,nonn,uned %O A174837 0,1 %A A174837 _Richard Choulet_, Mar 30 2010