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 A075821 #11 Sep 24 2018 16:53:14 %S A075821 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, %T A075821 39,41,43,44,47,48,49,51,52,53,56,57,59,61,63,64,67,68,69,71,72,73,75, %U A075821 76,77,79,81,83,84,87,88,89,91,92,93,96,97,99 %N A075821 List of possible last two digits (leading zeros omitted) of perfect powers. %C A075821 An equivalent definition: Numbers equal to the final two digits of their 21st, 41st, 61st, etc. powers. - _Henry Bottomley_, Nov 25 2004 %F A075821 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 %e A075821 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. %e A075821 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. %e A075821 11 is in the sequence since 11^21=7400249944258160101211 and the final two digits are 11. %Y A075821 Cf. A010809, A100990. %K A075821 full,fini,nonn,base %O A075821 1,3 %A A075821 _Zak Seidov_, Oct 14 2002 %E A075821 Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, Jun 06 2007