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 A075352 #4 Dec 05 2013 19:55:37 %S A075352 1,2,12,30,504,1320,43680,116280,6375600,17100720,1402410240, %T A075352 3776965920,8835488640,1022755734000,2478652606080,380634949094400, %U A075352 945378254620800,186127248627129600,470489622136934400,115590003914312928000 %N A075352 Group the natural numbers so that the product of the terms of the n-th group is just >= n!: (1), (2), (3, 4), (5, 6), (7, 8, 9), (10, 11, 12), (13, 14, 15, 16), (17, 18, 19, 20), (21, 22, 23, 24, 25), (26, 27, 28, 29, 30), ... Sequence gives product of numbers in each group. %Y A075352 Cf. A075353, A075354, A075355, A075356. %K A075352 nonn %O A075352 1,2 %A A075352 _Amarnath Murthy_, Sep 19 2002 %E A075352 More terms from _David Wasserman_, Jan 16 2005