

A129450


a(n) = smallest perfect power that begins and ends with digit n, 1 <= n <= 9; onedigit numbers are excluded.


1




OFFSET

1,1


LINKS

Table of n, a(n) for n=1..9.


EXAMPLE

a(8) = 202^3 = 8242408; there is no smaller perfect power that begins and ends with digit 8.


PROG

(MAGMA) PP:=[1] cat [ n: n in [2..9000000]  IsPower(n) ]; firstlast:=function(x); for n:=1 to #PP do k:=Intseq(PP[n], 10); if #k gt 1 and k[1] eq x and k[ #k] eq x then return PP[n]; end if; end for; return 1; end function; [ firstlast(d): d in [1..9] ]; // Klaus Brockhaus, Apr 16 2007


CROSSREFS

Cf. A001597 (perfect powers), A075786 (palindromic perfect powers), A128827.
Sequence in context: A121013 A287728 A218287 * A232279 A202887 A195275
Adjacent sequences: A129447 A129448 A129449 * A129451 A129452 A129453


KEYWORD

nonn,base,fini,full


AUTHOR

J. M. Bergot, Apr 12 2007


EXTENSIONS

Edited, corrected and extended by Klaus Brockhaus, Apr 16 2007


STATUS

approved



