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 A152909 #6 May 29 2015 21:16:58 %S A152909 1,2,3,5,8,12,20,34,57,98,170,300,536,966,1754,3210,5910,10944,20366, %T A152909 38064,71421,134480,254016,481176,913846,1739680,3318996,6344666, %U A152909 12150874,23310032,44787927,86181405,166057045,320370847,618821160 %N A152909 Largest k such that k! < 2^(2^n). %C A152909 a(4) = 8 is the largest number whose factorial can be stored as a 16-bit unsigned integer. %C A152909 a(5) = 12 is the largest number whose factorial can be stored as a 32-bit unsigned integer. %C A152909 a(7) = 34 is the largest number whose factorial can be stored as an IEEE single-precision floating-point number (limit is just under 2^128). %C A152909 a(10) = 170 is the largest number whose factorial can be stored as an IEEE double-precision floating-point number (limit is just under 2^1024). %C A152909 a(14) = 1754 is the largest number whose factorial can be stored in common implementations of quadruple-precision floating-point numbers. %Y A152909 Cf. A119906. %K A152909 nonn %O A152909 0,2 %A A152909 _Jon E. Schoenfield_, Dec 15 2008