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 A273148 #23 Jul 27 2024 02:54:02 %S A273148 0,1,4,2,164,19,3,5,16,14,12,10,8,6,8228,28,51,26,158,24,7,9,11,13,15, %T A273148 17,46,90,44,88,42,86,40,84,38,82,36,80,34,78,32,147,1975,18,22,20, %U A273148 255,73,1971,71,714,69,424,67,250,65,421,63,137,61,246,59,707 %N A273148 Left inverse of A274648. %C A273148 If A274648 is proved to be a permutation, then this is the full inverse of it. %H A273148 Benjamin Chaffin, <a href="/A273148/b273148.txt">Table of n, a(n) for n = 0..153</a> %H A273148 Benjamin Chaffin, <a href="/A273148/a273148.txt">Table of n, a(n) for n=0..1000000</a>. This represents the inverse of the first 3.2*10^11 terms of A274648. The 33242 entries of -1 correspond to values which have not yet appeared. The first missing number is 154. The largest term in this range is a(4287)=257890387560. %F A273148 a(n) = index of n in A274648; for all n >= 0, a(A274648(n)) = n. %e A273148 A274648(19) = 5, so a(5) = 19. %Y A273148 Cf. A274648, A005132. %K A273148 nonn %O A273148 0,3 %A A273148 _Benjamin Chaffin_, Oct 05 2016