A152909 Largest k such that k! < 2^(2^n).

1, 2, 3, 5, 8, 12, 20, 34, 57, 98, 170, 300, 536, 966, 1754, 3210, 5910, 10944, 20366, 38064, 71421, 134480, 254016, 481176, 913846, 1739680, 3318996, 6344666, 12150874, 23310032, 44787927, 86181405, 166057045, 320370847, 618821160

Offset

0,2

Comments

a(4) = 8 is the largest number whose factorial can be stored as a 16-bit unsigned integer.

a(5) = 12 is the largest number whose factorial can be stored as a 32-bit unsigned integer.

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).

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).

a(14) = 1754 is the largest number whose factorial can be stored in common implementations of quadruple-precision floating-point numbers.

Links

Table of n, a(n) for n=0..34.

Crossrefs

Cf. A119906.

Sequence in context: A117761 A274376 A018149 * A328597 A118604 A261694

Adjacent sequences: A152906 A152907 A152908 * A152910 A152911 A152912

Keyword

nonn

Author

Jon E. Schoenfield, Dec 15 2008

Status

approved