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 A094261 #13 Aug 17 2019 08:03:31 %S A094261 1,2,6,12,40,90,168,560,1296,2520,4400,14256,32760,64064,113400, %T A094261 187200,586432,1321920,2560896,4522000,7484400,11797632,35784320, %U A094261 78871968,150480000,263120000,433060992,681080400,1033305728,3044304000 %N A094261 a(n) = n(n-1)(n-3)(n-6)...(n-t), where t is the largest triangular number less than n; number of factors in the product is ceiling((sqrt(1+8*n)-1)/2). %e A094261 a(8) = 8*(8-1)*(8-3)*(8-6) = 8*7*5*2 = 560. %p A094261 a:=n->product(n-k*(k+1)/2,k=0..ceil((sqrt(1+8*n)-1)/2)-1): seq(a(n),n=1..35); # _Emeric Deutsch_, Feb 03 2006 %Y A094261 Cf. A057944, A094262. %K A094261 nonn %O A094261 1,2 %A A094261 _Amarnath Murthy_, Apr 26 2004 %E A094261 Corrected and extended by _Emeric Deutsch_, Feb 03 2006