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 A053236 #13 Oct 27 2023 22:00:45 %S A053236 23,54,59,84,114,138,149,172,177,232,257,281,293,311,355,392,417,422, %T A053236 434,445,481,506,561,596,601,644,656,686,715,745,763,775,798,809,853, %U A053236 864,944,955,979,984,1013,1018,1061,1072,1140,1164,1187,1192,1222,1227 %N A053236 Numbers n such that A053230(n) = 4. %H A053236 Reinhard Zumkeller, <a href="/A053236/b053236.txt">Table of n, a(n) for n = 1..10000</a> %p A053236 with(numtheory): f := [seq( `if`((sigma(i+1) > sigma(i)),i,print( )), i=1..8000)]; %p A053236 seq( `if`(f[i+1] - f[i] = 4,i,print( )), i=1..3000); %o A053236 (Haskell) %o A053236 import Data.List (elemIndices) %o A053236 a053236 n = a053236_list !! (n-1) %o A053236 a053236_list = map (+ 1) $ elemIndices 4 a053230_list %o A053236 -- _Reinhard Zumkeller_, May 07 2012 %Y A053236 Cf. A000203, A053224, A053230, A053231, A053232, A053233, A053234, A053235, A053237. %K A053236 nonn %O A053236 1,1 %A A053236 _Asher Auel_, Jan 10 2000