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 A381230 #51 Mar 14 2025 02:34:32 %S A381230 6,0,17,45,13,42,938,920,57403,7865,15862,313445,54988,53976,57573, %T A381230 61372,83445,14998,360213,57322,59858,2070497,2021631,14918,58001, %U A381230 1394543,79664,2056395,85989,11,8,71662,5495575,5652770,360110,2070250,5947332,5514279,5514772,2015129,78877,305403,1031,1869352,5652707,4823241 %N A381230 Index of first occurrence of n in A000319, or -1 if n never appears there. %C A381230 If a(57) is not -1, then a(57) > 14333074. - _Tim Peters_, Mar 13 2025 %H A381230 Tim Peters, <a href="/A381230/b381230.txt">Table of n, a(n) for n = 0..56</a> %e A381230 0 is the 6th term of A000319, so a(0) = 6. 1 is the 0th term, so a(1) = 0. %Y A381230 Cf. A000319, A381231. %K A381230 nonn %O A381230 0,1 %A A381230 _N. J. A. Sloane_, Feb 28 2025 %E A381230 a(8)-a(10) from _Hugo Pfoertner_, Feb 28 2025 %E A381230 a(11)-a(31) from _Tim Peters_, Mar 01 2025 %E A381230 a(32) from _Tim Peters_, Mar 02 2025 %E A381230 a(33)-a(45) from _Tim Peters_, Mar 04 2025