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 A112990 #12 Jun 24 2024 22:27:28 %S A112990 1,2,5,3,9,4,12,6,7,8,19,10,23,11,13,14,30,15,34,16,17,18,41,20,21,22, %T A112990 24,25,52,26,55,27,28,29,31,32,65,33,35,36,73,37,77,38,39,40,85,42,43, %U A112990 44,45,46,95,47,48,49,50,51,105,53,110,54,56,57,58,59,121,60,61,62,128 %N A112990 Inverse of A089088. %H A112990 Reinhard Zumkeller, <a href="/A112990/b112990.txt">Table of n, a(n) for n = 1..1000</a> %H A112990 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A112990 (Haskell) %o A112990 import Data.List (elemIndex) %o A112990 import Data.Maybe (fromJust) %o A112990 a112990 = (+ 1) . fromJust . (`elemIndex` a089088_list) %o A112990 -- _Reinhard Zumkeller_, Feb 27 2013 %Y A112990 Cf. A112978. %K A112990 nonn %O A112990 1,2 %A A112990 _Reinhard Zumkeller_, Oct 08 2005