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 A092603 #16 Sep 08 2022 08:45:13 %S A092603 1,2,4,8,15,31,62,126,283,539,1177,2459,4969,10781,22297,45116,95759, %T A092603 201615,400755,830859,1741455,3505627,7099561,14607199,30112789, %U A092603 60176505,121626832,247652036,504389269,1010060135,2030792857,4102303316,8289676399,16659582365 %N A092603 a(n) = Sum_{k=1..n} min(k!, binomial(n,k)). %C A092603 Upper bound on A088532(n). %C A092603 The number of patterns of length k in a permutation of length n is bounded above by k! and binomial(n,k). The total number of patterns in a permutation of length n is therefore bounded above by the sum of the smaller of these two upper bounds. %F A092603 a(n) ~ 2^n. - _Vaclav Kotesovec_, Aug 03 2015 %t A092603 Table[Sum[Min[k!, Binomial[n, k]], {k, 1, n}], {n, 1, 40}] %o A092603 (PARI) a(n) = sum(k=1, n, min(k!, binomial(n, k))); \\ _Michel Marcus_, Nov 14 2019 %o A092603 (Magma) [&+[Min(Factorial(k),Binomial(n,k)):k in [1..n]]:n in [1..34]]; // _Marius A. Burtea_, Nov 14 2019 %Y A092603 Cf. A088532. %K A092603 easy,nonn %O A092603 1,2 %A A092603 _Rob Pratt_, Apr 10 2004