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 A354487 #11 Feb 16 2025 08:34:03 %S A354487 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, %T A354487 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, %U A354487 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,7,1,1,1,1,1,1,1,1,1,1,1,1,1,91,1,1,1,1,1,1,1,1,1,1 %N A354487 Triangle read by rows: T(n,k) is the denominator of the n-th term of the Somos-k sequence, 4 <= k <= n. %H A354487 Pontus von Brömssen, <a href="/A354487/b354487.txt">Rows n = 4..36, flattened</a> %H A354487 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SomosSequence.html">Somos Sequence</a> %H A354487 Wikipedia, <a href="https://en.wikipedia.org/wiki/Somos_sequence">Somos sequence</a> %F A354487 T(n,k) = 1 if 4 <= k <= 7 or n < A030127(k). %e A354487 Triangle begins: %e A354487 n\k| 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 %e A354487 ---+------------------------------------------------------ %e A354487 4 | 1 %e A354487 5 | 1 1 %e A354487 6 | 1 1 1 %e A354487 7 | 1 1 1 1 %e A354487 8 | 1 1 1 1 1 %e A354487 9 | 1 1 1 1 1 1 %e A354487 10 | 1 1 1 1 1 1 1 %e A354487 11 | 1 1 1 1 1 1 1 1 %e A354487 12 | 1 1 1 1 1 1 1 1 1 %e A354487 13 | 1 1 1 1 1 1 1 1 1 1 %e A354487 14 | 1 1 1 1 1 1 1 1 1 1 1 %e A354487 15 | 1 1 1 1 1 1 1 1 1 1 1 1 %e A354487 16 | 1 1 1 1 1 1 1 1 1 1 1 1 1 %e A354487 17 | 1 1 1 1 7 1 1 1 1 1 1 1 1 1 %e A354487 18 | 1 1 1 1 91 1 1 1 1 1 1 1 1 1 1 %e A354487 19 | 1 1 1 1 2275 7 1 1 1 1 1 1 1 1 1 1 %e A354487 20 | 1 1 1 1 138775 7 5 1 1 1 1 1 1 1 1 1 1 %Y A354487 Cf. A354486 (numerators), A030127. %K A354487 nonn,tabl,frac %O A354487 4,96 %A A354487 _Pontus von Brömssen_, May 28 2022