cp's OEIS Frontend

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.

A052133 CONTINUANT transform of 0, 1, 1, 2, 1, 3, 2, 3, ... (A002487).

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%I A052133 #12 Nov 25 2014 05:21:19
%S A052133 0,1,1,3,4,15,34,117,151,721,2314,12291,26896,146771,467209,2015607,
%T A052133 2482816,14429687,60201564,435840635,1367723469,11377628387,
%U A052133 58255865404,419168686215,896593237834,6695321351053,34373199993099,281680921295845,879415963880634
%N A052133 CONTINUANT transform of 0, 1, 1, 2, 1, 3, 2, 3, ... (A002487).
%H A052133 Alois P. Heinz, <a href="/A052133/b052133.txt">Table of n, a(n) for n = 0..400</a>
%H A052133 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%p A052133 b:= proc(n) option remember; `if`(n<2, n,
%p A052133       `if`(irem(n, 2, 'r')=0, b(r), b(r) + b(r+1)))
%p A052133     end:
%p A052133 a:= proc(n) option remember; `if`(n<-1, 0,
%p A052133       `if`(n<0, 1, b(n)*a(n-1)+a(n-2)))
%p A052133     end:
%p A052133 seq(a(n), n=0..35);  # _Alois P. Heinz_, Aug 06 2013
%t A052133 b[n_] := b[n] = If[n < 2, n, {q, r} = QuotientRemainder[n, 2]; If[r == 0, b[q], b[q] + b[q+1]]]; a[n_] := a[n] = If[n < -1, 0, If[n < 0, 1, b[n]*a[n-1] + a[n-2]]]; Table[a[n], {n, 0, 35}] (* _Jean-François Alcover_, Nov 25 2014, after _Alois P. Heinz_ *)
%Y A052133 Cf. A071898.
%K A052133 nonn
%O A052133 0,4
%A A052133 _N. J. A. Sloane_, Jul 18 2002