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 A115408 #9 Sep 16 2014 16:16:03 %S A115408 1,6,15,3,2,5,4,28,45,10,66,9,14,91,13,8,7,120,12,11,153,190,21,231, %T A115408 276,20,325,378,435,496,27,561,630,26,703,19,780,18,861,946,1035,17, %U A115408 16,25,1128,24,1225,1326,1431,23,22,1540,1653,36,1770,1891,2016,2145 %N A115408 Integer permutation induced by A024431. %C A115408 a(n) = A115406(n)*(A115406(n)-1)/2 + A115407(n) + 1; %C A115408 inverse: A115409. %H A115408 Reinhard Zumkeller, <a href="/A115408/b115408.txt">Table of n, a(n) for n = 1..1000</a> %H A115408 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A115408 (Haskell) %o A115408 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A115408 a115408 = (+ 1) . fromJust . (`elemIndex` a115409_list) %o A115408 -- _Reinhard Zumkeller_, Sep 16 2014 %K A115408 nonn %O A115408 1,2 %A A115408 _Reinhard Zumkeller_, Jan 22 2006