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 A129450 a(n) = smallest perfect power that begins and ends with digit n, 1 <= n <= 9; one-digit numbers are excluded. 1
 121, 21952, 343, 484, 5625, 676, 79507, 8242408, 9409 (list; graph; refs; listen; history; text; internal format)
 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

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Last modified June 21 21:50 EDT 2024. Contains 373559 sequences. (Running on oeis4.)