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 A370391 #43 Apr 04 2024 10:40:13 %S A370391 1,7,35,154,636,2533,9861,37810,143451,540155,2022735,7543771, %T A370391 28048829,104050724,385320419,1425038684,5264963100,19437087382, %U A370391 71715418017,264483764116,975070823122,3593840295815,13243217176106,48793364067681,179753027448972 %N A370391 Expansion of (1 - 2*x)/(1 - 9*x + 28*x^2 - 35*x^3 + 15*x^4 - x^5). %C A370391 The sequence is constructed by a truncated version of Pascal's Triangle. %C A370391 1 %C A370391 1 1 %C A370391 1 2 1 %C A370391 1 3 3 1 %C A370391 1 4 6 4 %C A370391 1 5 10 10 4 %C A370391 1 6 15 20 14 %C A370391 7 21 35 34 14 %C A370391 7 28 56 69 48 %C A370391 35 84 125 117 48 %C A370391 35 119 209 242 165 %C A370391 ... %C A370391 After truncation the sequence appears as the left vertical column. The right column sequence can be in A370051. %C A370391 a(n) arises from the Gambler's Ruin problem and represents the number of ways a gambler is ruined after starting with $7 with a maximum $11 causing retirement. %H A370391 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (9,-28,35,-15,1). %F A370391 a(n) = 9*a(n-1) - 28*a(n-2) + 35*a(n-3) - 15*a(n-4) + a(n-5). %t A370391 LinearRecurrence[{9, -28, 35, -15, 1}, {1, 7,35,154,636}, 25] (* _James C. McMahon_, Mar 12 2024 *) %Y A370391 Cf. A211216, A224422, A221863, A122588, A370074, A370051. %K A370391 nonn,easy %O A370391 0,2 %A A370391 _Peter Morris_, Feb 22 2024