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 A164961 #23 May 04 2025 16:43:45 %S A164961 1,2,2,12,24,12,120,360,360,120,1680,6720,10080,6720,1680,30240, %T A164961 151200,302400,302400,151200,30240,665280,3991680,9979200,13305600, %U A164961 9979200,3991680,665280,17297280,121080960,363242880,605404800,605404800 %N A164961 Triangle read by rows: T[n,m] = quadruple factorials A001813(n) * binomials A007318(n,m). %C A164961 Row sums give A052714. - _Tilman Neumann_, Sep 07 2009 %C A164961 Triangle T(n,k), read by rows, given by (2, 4, 6, 8, 10, 12, 14, ...) DELTA (2, 4, 6, 8, 10, 12, 14, ...) where DELTA is the operator defined in A084938. - _Philippe Deléham_, Jan 07 2012 %H A164961 <a href="https://web.archive.org/web/20190424234154/http://tilman-neumann.de/docs/A164961.txt">More terms</a>. - _Tilman Neumann_, Sep 07 2009 %F A164961 T(n,k) = A085881(n,k)*2^n. - _Philippe Deléham_, Jan 07 2012 %F A164961 Recurrence equation: T(n+1,k) = (4*n+2)*(T(n,k) + T(n,k-1)). - _Peter Bala_, Jul 15 2012 %F A164961 E.g.f.: 1/sqrt(1-4*x-4*x*y). - _Peter Bala_, Jul 15 2012 %e A164961 Triangle begins: %e A164961 1 %e A164961 2, 2 %e A164961 12, 24, 12 %e A164961 120, 360, 360, 120 %e A164961 1680, 6720, 10080, 6720, 1680 %Y A164961 Cf. A001813, A007318, A052714 (row sums), A084938, A085881. %K A164961 nonn,tabl %O A164961 0,2 %A A164961 _Tilman Neumann_, Sep 02 2009