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 A224249 #13 Jun 27 2023 11:11:07 %S A224249 0,0,0,0,4,63,665,5982,49748,396642,3089010,23745117,181282899, %T A224249 1379847138,10496697584,79928658289,609847716251,4665446254886, %U A224249 35801131210504,275638351332190,2129514056354378,16509890253429971,128449405928666831,1002835093225654416,7856166360951643384 %N A224249 Number of permutations in S_n containing exactly 2 increasing subsequences of length 4. %H A224249 Andrew R. Conway and Anthony J. Guttmann, <a href="https://arxiv.org/abs/2306.12682">Counting occurrences of patterns in permutations</a>, arXiv:2306.12682 [math.CO], 2023. See pp. 16, 24, 25. %H A224249 B. Nakamura and D. Zeilberger, <a href="http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimhtml/Gwilf.html">Using Noonan-Zeilberger Functional Equations to enumerate (in Polynomial Time!) Generalized Wilf classes</a> %H A224249 B. Nakamura and D. Zeilberger, <a href="https://doi.org/10.1016/j.aam.2012.10.003">Using Noonan-Zeilberger Functional Equations to enumerate (in Polynomial Time!) Generalized Wilf classes</a>, Adv. in Appl. Math. 50 (2013), 356-366. %p A224249 # programs can be obtained from the Nakamura and Zeilberger link. %Y A224249 Cf. A005802, A217057. %K A224249 nonn %O A224249 1,5 %A A224249 _Brian Nakamura_, Apr 02 2013