A101515 Symmetric square array, read by antidiagonals, such that the inverse binomial transform of row n forms the sequence: {C(n,k)*A101514(k), 0<=k<=n}, where A101514 equals the main diagonal shift right.
1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 7, 4, 1, 1, 5, 13, 13, 5, 1, 1, 6, 21, 35, 21, 6, 1, 1, 7, 31, 77, 77, 31, 7, 1, 1, 8, 43, 146, 236, 146, 43, 8, 1, 1, 9, 57, 249, 596, 596, 249, 57, 9, 1, 1, 10, 73, 393, 1290, 2037, 1290, 393, 73, 10, 1, 1, 11, 91, 585, 2486, 5772, 5772, 2486, 585
Offset: 0
Examples
Rows begin: [_1,1,1,1,1,1,1,1,1,...], [1,_2,3,4,5,6,7,8,9,...], [1,3,_7,13,21,31,43,57,73,...], [1,4,13,_35,77,146,249,393,585,...], [1,5,21,77,_236,596,1290,2486,4387,...], [1,6,31,146,596,_2037,5772,13987,29987,...], [1,7,43,249,1290,5772,_21695,67943,181811,...], [1,8,57,393,2486,13987,67943,_277966,951051,...], [1,9,73,585,4387,29987,181811,951051,_4198635,...],... The inverse binomial transform of the rows of this array are generated from the products of the main diagonal with rows of Pascal's triangle: BINOMIAL[1*1] = [_1,1,1,1,1,1,1,1,1,...], BINOMIAL[1*1,1*1] = [1,_2,3,4,5,6,7,8,9,...], BINOMIAL[1*1,1*2,2*1] = [1,3,_7,13,21,31,43,57,73,...], BINOMIAL[1*1,1*3,2*3,7*1] = [1,4,13,_35,77,146,249,393,...], BINOMIAL[1*1,1*4,2*6,7*4,35*1] = [1,5,21,77,_236,596,1290,...], BINOMIAL[1*1,1*5,2*10,7*10,35*5,236*1] = [1,6,31,146,596,_2037,...],...
Programs
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PARI
T(n,k)=if(n<0 || k<0,0,if(n==0 || k==0,1,if(n>k,T(k,n), 1+sum(j=1,k,binomial(k,j)*binomial(n,j)*T(j-1,j-1));)))
Comments