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A129450
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a(n) = smallest perfect power that begins and ends with digit n, 1 <= n<= 9; one-digit numbers are excluded.
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1
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OFFSET
| 1,1
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EXAMPLE
| a(8) = 202^3 = 8242408; there is no smaller perfect power that begins and ends with digit 8.
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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 */
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CROSSREFS
| Cf. A001597 (perfect powers), A075786 (palindromic perfect powers), A128827.
Sequence in context: A178512 A050740 A121013 * A202887 A195275 A082489
Adjacent sequences: A129447 A129448 A129449 * A129451 A129452 A129453
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KEYWORD
| nonn,base,fini,full
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AUTHOR
| J. M. Bergot (thekingfishb(AT)yahoo.ca), Apr 12 2007
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EXTENSIONS
| Edited, corrected and extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Apr 16 2007
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