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 A336816 #14 Nov 23 2020 17:07:55
%S A336816 1,2,3,5,7,4,13,25,33,8,49,6,97,14,9,193,241,34,481,10,15,50,961,26,
%T A336816 1921,98,2881,16,3841,11,7681,15361,51,242,17,35,18433,482,99,27,
%U A336816 36865,18,73729,52,36,962,147457,194,294913,1922,243,100,442369,2882,53,28
%N A336816 Inverse permutation to A305325.
%H A336816 Rémy Sigrist, <a href="/A336816/b336816.txt">Table of n, a(n) for n = 1..10000</a>
%H A336816 Rémy Sigrist, <a href="/A336816/a336816.gp.txt">PARI program for A336816</a>
%H A336816 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F A336816 a(A000961(n)) = 1 + Sum_{k = 1..n-1} A305215(k).
%e A336816 A305325(18) = 42, so a(42) = 18.
%o A336816 (PARI) See Links section.
%Y A336816 Cf. A000961, A305215, A305325.
%K A336816 nonn
%O A336816 1,2
%A A336816 _Rémy Sigrist_, Nov 21 2020