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 A353707 #19 May 06 2022 12:51:48 %S A353707 0,0,0,-1,1,0,0,-1,-1,-2,3,-1,2,-2,-2,-3,3,-2,4,-3,0,-2,5,-4,3,-1,2, %T A353707 -3,3,-6,2,0,0,-1,5,-4,3,-1,2,-3,3,-2,2,-3,-3,-4,5,-6,4,-1,2,-3,7,-4, %U A353707 3,-3,4,-4,3,-3,4,-4,-1,-3,5,-5,6 %N A353707 n appears in A121216 a(n) steps earlier than expected. %C A353707 It appears that a positive number n appears in A121216 at about the n-th term; if in fact A121216(k) = n, then a(n) = n - k. %C A353707 An equivalent definition uses the inverse to A121216: a(n) = n - A225047(n). %H A353707 Rémy Sigrist, <a href="/A353707/b353707.txt">Table of n, a(n) for n = 1..10000</a> %H A353707 Rémy Sigrist, <a href="/A353707/a353707.gp.txt">PARI program</a> %e A353707 A121216(8) = 11, so 11 has appeared 3 steps early, therefore a(11) = 11 - 8 = 3. %o A353707 (PARI) See Links section. %Y A353707 Cf. A121216, A225047, A353706. %K A353707 sign %O A353707 1,10 %A A353707 _N. J. A. Sloane_, May 05 2022