cp's OEIS Frontend

A260638 Irregular table: list of symmetric n X n matrices made from 2-binomial coefficients, read by rows, where the k-th row of any n X n matrix is filled with binomial coefficients [k-1,k-1]..[k+n-2,k-1] (for q=2).

%I A260638 #25 Nov 22 2015 15:16:46
%S A260638 1,1,1,1,3,1,1,1,1,3,7,1,7,35,1,1,1,1,1,3,7,15,1,7,35,155,1,15,155,
%T A260638 1395,1,1,1,1,1,1,3,7,15,31,1,7,35,155,651,1,15,155,1395,11811,1,31,
%U A260638 651,11811,200787,1,1,1,1,1,1,1,3,7,15,31,63,1,7,35,155
%N A260638 Irregular table: list of symmetric n X n matrices made from 2-binomial coefficients, read by rows, where the k-th row of any n X n matrix is filled with binomial coefficients [k-1,k-1]..[k+n-2,k-1] (for q=2).
%C A260638 The determinant of the n X n matrix is 2^((n/6)*(2*n^2 - 3*n + 1)), that is, A185995(n-1).
%C A260638 The permanent is in A260639.
%H A260638 G. C. Greubel, <a href="/A260638/b260638.txt">Table of n, a(n) for n = 1..819</a>
%e A260638 The irregular table starts:
%e A260638 1;
%e A260638 1, 1;
%e A260638 1, 3;
%e A260638 1, 1, 1;
%e A260638 1, 3, 7;
%e A260638 1, 7, 35;
%t A260638 Flatten@Flatten@Table[Table[QBinomial[r + c, r, 2], {r, 0, n}, {c, 0, n}], {n, 0, 5}]
%Y A260638 Cf. A000225, A006095, A185995, A260639.
%K A260638 nonn,easy,tabf
%O A260638 1,5
%A A260638 _Arkadiusz Wesolowski_, Nov 11 2015