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 A321622 #11 Mar 27 2020 13:59:34 %S A321622 1,1,1,0,1,1,1,1,1,1,2,4,2,1,1,6,10,7,3,1,1,18,31,19,10,4,1,1,57,97, %T A321622 61,29,13,5,1,1,186,316,196,96,40,16,6,1,1,622,1054,652,316,136,52,19, %U A321622 7,1,1,2120,3586,2210,1072,458,181,65,22,8,1,1 %N A321622 The Riordan square of the Fine numbers, triangle read by rows, T(n, k) for 0 <= k<= n. %C A321622 Fine numbers as defined in A000957 have a(0) = 0 whereas our variant has a(0) = 1. The rows sums of the triangle are |A002420|. %e A321622 [0] [ 1] %e A321622 [1] [ 1, 1] %e A321622 [2] [ 0, 1, 1] %e A321622 [3] [ 1, 1, 1, 1] %e A321622 [4] [ 2, 4, 2, 1, 1] %e A321622 [5] [ 6, 10, 7, 3, 1, 1] %e A321622 [6] [ 18, 31, 19, 10, 4, 1, 1] %e A321622 [7] [ 57, 97, 61, 29, 13, 5, 1, 1] %e A321622 [8] [ 186, 316, 196, 96, 40, 16, 6, 1, 1] %e A321622 [9] [ 622, 1054, 652, 316, 136, 52, 19, 7, 1, 1] %p A321622 # The function RiordanSquare is defined in A321620. %p A321622 Fine := 1 + (1 - sqrt(1 - 4*x))/(3 - sqrt(1 - 4*x)); RiordanSquare(Fine, 10); %t A321622 (* The function RiordanSquare is defined in A321620. *) %t A321622 FineGF = 1 + (1 - Sqrt[1 - 4x])/(3 - Sqrt[1 - 4x]); %t A321622 RiordanSquare[FineGF, 10] (* _Jean-François Alcover_, Jun 15 2019, from Maple *) %o A321622 (Sage) # uses[riordan_square from A321620] %o A321622 riordan_square(1 + (1 - sqrt(1 - 4*x))/(3 - sqrt(1 - 4*x)), 10) %Y A321622 T(n, 0) = A000957 (Fine), |A002420| (row sums), A000007 (alternating row sums). %Y A321622 Cf. A321620. %K A321622 nonn,tabl %O A321622 0,11 %A A321622 _Peter Luschny_, Nov 22 2018