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 A087727 #16 Nov 09 2019 10:43:03 %S A087727 1,1,5,1,14,42,1,28,210,462,1,48,660,3432,6006,1,75,1650,15015,60060, %T A087727 87516,1,110,3575,50050,340340,1108536,1385670,1,154,7007,140140, %U A087727 1429428,7759752,21339318,23371634,1,208,12740,346528,4938024,39504192,178474296,424938800,414315330 %N A087727 Triangle read by rows: T(n,k) = (2 * (binomial(n,k)) * (n + 2 * k + 3)!)/((k + 1)! * (k + 2)! * (n + 3)!). %e A087727 Triangle begins: %e A087727 1; %e A087727 1, 5; %e A087727 1, 14, 42; %e A087727 1, 28, 210, 462; %e A087727 ... %o A087727 (PARI) t(n, k) = (2 * (binomial(n,k)) * (n + 2*k + 3)!)/((k + 1)! * (k + 2)! * (n + 3)!) \\ _Michel Marcus_, Jun 26 2013 %Y A087727 Row sums give A087659. Right diagonal gives A005789. %K A087727 nonn,tabl,easy %O A087727 0,3 %A A087727 _Bill Gosper_, Sep 30 2003 %E A087727 More terms from _Ray Chandler_, Sep 30 2003