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 A382085 #7 Mar 17 2025 22:19:18 %S A382085 2,3,4,5,6,7,8,9,10,11,12,13,14,15,13,12,11,10,11,12,13,14,15,13,9,8, %T A382085 7,4,5,6,7,8,10,11,12,10,5,6,7,8,9,7,6,7,8,7,8,9,7,6,7,9,10,11,12,10, %U A382085 9,8,5,6,7,8,9,8,9,10,8,7,6,7,9,10,11,12,10,9,10 %N A382085 a(n) is the unique k such that A382067(n) * A382067(n+1) = k!. %H A382085 Rémy Sigrist, <a href="/A382085/b382085.txt">Table of n, a(n) for n = 1..10000</a> %H A382085 Rémy Sigrist, <a href="/A382085/a382085.gp.txt">PARI program</a> %F A382085 a(n) = A084558(A382067(n) * A382067(n+1)). %e A382085 A382067(15) * A382067(15+1) = 2027025 * 3072 = 13!, so a(15) = 13. %o A382085 (PARI) \\ See Links section. %Y A382085 Cf. A084558, A382067. %K A382085 nonn %O A382085 1,1 %A A382085 _Rémy Sigrist_, Mar 15 2025