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 A190152 #15 Dec 30 2017 03:30:50 %S A190152 1,1,1,1,10,1,1,28,35,1,1,55,210,84,1,1,91,715,924,165,1,1,136,1820, %T A190152 5005,3003,286,1,1,190,3876,18564,24310,8008,455,1,1,253,7315,54264, %U A190152 125970,92378,18564,680,1,1,325,12650,134596,490314,646646,293930,38760,969,1 %N A190152 Triangle of binomial coefficients binomial(3*n-k,3*n-3*k). %C A190152 From _R. J. Mathar_, Mar 15 2013: (Start) %C A190152 The matrix inverse starts %C A190152 1; %C A190152 -1,1; %C A190152 9,-10,1; %C A190152 -288,322,-35,1; %C A190152 22356,-25003,2730,-84,1; %C A190152 -3428973,3835026,-418825,12936,-165,1; %C A190152 914976405,-1023326973,111759115,-3452449,44187,-286,1; %C A190152 ... (End) %H A190152 Nathaniel Johnston, <a href="/A190152/b190152.txt">Rows n = 0..100, flattened</a> %e A190152 Triangle begins: %e A190152 1 %e A190152 1, 1 %e A190152 1, 10, 1 %e A190152 1, 28, 35, 1 %e A190152 1, 55, 210, 84, 1 %e A190152 1, 91, 715, 924, 165, 1 %e A190152 1, 136, 1820, 5005, 3003, 286, 1 %e A190152 1, 190, 3876, 18564, 24310, 8008, 455, 1 %e A190152 1, 253, 7315, 54264, 125970, 92378, 18564, 680, 1 %e A190152 ... %t A190152 Flatten[Table[Binomial[3n - k, 3n - 3k], {n, 0, 9}, {k, 0, n}]] %o A190152 (Maxima) create_list(binomial(3*n-k,3*n-3*k),n,0,9,k,0,n); %o A190152 (PARI) for(n=0,10, for(k=0,n, print1(binomial(3*n-k, 3*(n-k)), ", "))) \\ _G. C. Greubel_, Dec 29 2017 %Y A190152 Cf. A000447 (first subdiagonal), A053135 (second subdiagonal), A060544 (second column), A190088, A190153 (row sums), A190154 (diagonal sums). %K A190152 nonn,easy,tabl %O A190152 0,5 %A A190152 _Emanuele Munarini_, May 05 2011