A075821 List of possible last two digits (leading zeros omitted) of perfect powers.

0, 1, 3, 4, 7, 8, 9, 11, 12, 13, 16, 17, 19, 21, 23, 24, 25, 27, 28, 29, 31, 32, 33, 36, 37, 39, 41, 43, 44, 47, 48, 49, 51, 52, 53, 56, 57, 59, 61, 63, 64, 67, 68, 69, 71, 72, 73, 75, 76, 77, 79, 81, 83, 84, 87, 88, 89, 91, 92, 93, 96, 97, 99

Offset

1,3

Comments

An equivalent definition: Numbers equal to the final two digits of their 21st, 41st, 61st, etc. powers. - Henry Bottomley, Nov 25 2004

Links

Table of n, a(n) for n=1..63.

Formula

Consists of all numbers below 100 except those which are a multiple of 2 but not 4 and those which are a multiple of 5 but not 25. - Henry Bottomley, Nov 25 2004

Example

With leading zeros, the initial terms are 00, 01, 03, 04, 07, 08, 09. Corresponding smallest perfect powers are 100, 2401, 658503, 2304, 16807, 140608, 2209.
1 (01!) is OK because the perfect power 2401=49^2 ends with 01. 9 (09!) is OK because the perfect power 2209=47^2 ends with 09.
11 is in the sequence since 11^21=7400249944258160101211 and the final two digits are 11.

Crossrefs

Cf. A010809, A100990.

Sequence in context: A092754 A061094 A100991 * A120515 A047545 A296352

Adjacent sequences: A075818 A075819 A075820 * A075822 A075823 A075824

Keyword

full,fini,nonn,base

Author

Zak Seidov, Oct 14 2002

Extensions

Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, Jun 06 2007

Status

approved