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A076442 Odd-digit perfect powers. 1
1, 9, 1331, 3375, 35937, 59319, 357911, 753571, 759375, 5177717, 5359375, 5735339, 9393931, 17373979, 37595375, 39135393, 37159393753, 99317171591 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

No other terms < 1.3*10^11. - Robert G. Wilson v, Dec 17 2002

LINKS

Table of n, a(n) for n=1..18.

MATHEMATICA

NextOddNbr[n_] := Block[{d = If[ EvenQ[n], IntegerDigits[n + 1], IntegerDigits[n + 2]], l}, l = Length[d]; While[l != 1, If[ EvenQ[ d[[l]]], d[[l]]++ ]; If[d[[l]] > 9, d[[l - 1]]++; d[[l]] = 1]; l-- ]; If[ EvenQ[ d[[1]]], d[[1]]++ ]; If[ d[[1]] > 9, d[[1]] = 11]; FromDigits[d]] k = 1; Do[ If[ !PrimeQ[k] && Apply[GCD, Last[ Transpose[ FactorInteger[k]]]] > 1, Print[k]]; k = NextOddNbr[k], {n, 1, 10^8}]

CROSSREFS

Cf. A001597, A014261, A075787.

Sequence in context: A276823 A020261 A266864 * A076704 A117053 A270067

Adjacent sequences:  A076439 A076440 A076441 * A076443 A076444 A076445

KEYWORD

base,nonn

AUTHOR

Robert G. Wilson v and Zak Seidov, Oct 11 2002

EXTENSIONS

Extended by Robert G. Wilson v, Dec 17 2002

STATUS

approved

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Last modified January 26 23:05 EST 2020. Contains 331289 sequences. (Running on oeis4.)