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 A362194 #17 Apr 21 2023 05:12:55
%S A362194 1,1,2,5,12,27,58,120,239,457,838,1475,2498,4083,6462,9934,14877,
%T A362194 21761,31162,43777,60440,82139,110034,145476,190027,245481,313886,
%U A362194 397567,499150,621587,768182,942618,1148985,1391809,1676082,2007293,2391460,2835163,3345578,3930512
%N A362194 Number of Grassmannian permutations of size n that avoid a pattern, sigma, where sigma is a pattern of size 7 with exactly one descent.
%C A362194 A permutation is said to be Grassmannian if it has at most one descent. The definition for sigma is a pattern of size 7 with exactly one descent. For example, sigma can be chosen to be 1247356, 2413567, 3671245, 5712346, etc.
%H A362194 Juan B. Gil and Jessica Tomasko, <a href="https://doi.org/10.54550/ECA2022V2S4PP6">Restricted Grassmannian permutations</a>, ECA 2:4 (2022) Article S4PP6.
%H A362194 <a href="/index/Rec#order_07">Index entries for linear recurrences with constant coefficients</a>, signature (7,-21,35,-35,21,-7,1).
%F A362194 a(n) = 1 + Sum_{i=2..6} binomial(n, i).
%F A362194 a(n) = A008859(n) - n.
%F A362194 G.f.: (1-6*x+16*x^2-23*x^3+19*x^4-8*x^5+2*x^6)/(1-x)^7.
%F A362194 E.g.f.: exp(x)*(720 + 360*x^2 + 120*x^3 + 30*x^4 + 6*x^5 + x^6)/720. - _Stefano Spezia_, Apr 20 2023
%o A362194 (PARI) a(n) = 1 + sum(i=2, 6, binomial(n,i)) \\ _Andrew Howroyd_, Apr 20 2023
%Y A362194 Cf. A000325, A008859, A362193.
%K A362194 nonn,easy
%O A362194 0,3
%A A362194 _Jessica A. Tomasko_, Apr 20 2023