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 A222482 #15 Feb 16 2025 08:33:19 %S A222482 3,20,22,40,68,248,7163,28663,50059,64574,638169,761733,2537764, %T A222482 2925739,3363073,4977902,5646039,57212854,159650555,219684539, %U A222482 453524713,459239955,2002180165,3234082460,14965375439,50298730245,89316768769,464076054936,520232391320 %N A222482 Engel expansion of cos(1)/(1+cos(1)). %C A222482 Cf. A006784 for definition of Engel expansion. %H A222482 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/EngelExpansion.html">Engel Expansion</a> %H A222482 Wikipedia, <a href="https://en.wikipedia.org/wiki/Engel_expansion">Engel Expansion</a> %H A222482 <a href="/index/El#Engel">Index entries for sequences related to Engel expansions</a> %F A222482 cos(1)/(1+cos(1)) = 1/(1+1/cos(1)) = 1/(1+sec(1)). %e A222482 0.35077679479523758155811675... %p A222482 Digits:= 1000: %p A222482 b:= evalf(1/(1+1/cos(1))): engel:= (r, n)-> `if`(n=0 or r=0, NULL, [ceil(1/r), engel(r*ceil(1/r)-1, n-1)][]): %p A222482 engel(b, 39); %Y A222482 Cf. A222480 (decimal expansion), A222481 (continued fraction), A049470 (cos(1)), A073448 (1/cos(1)). %K A222482 nonn %O A222482 1,1 %A A222482 _Alois P. Heinz_, Feb 21 2013