A016057 - OEIS

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A016057

Pseudo-powers to base 3: numbers k that are not powers of 3 such that k divides 2^k + 1.

171, 513, 1539, 3249, 4617, 9747, 13203, 13851, 29241, 39609, 41553, 61731, 87723, 97641, 118827, 124659, 185193, 250857, 263169, 292923, 354537, 356481, 373977, 555579, 752571, 789507, 878769, 1063611, 1069443, 1121931, 1172889, 1666737, 1855179, 2152089, 2257713

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OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..1000

MATHEMATICA

Do[ If[ PowerMod[ 2, n, n ] + 1 == n, If[ ! IntegerQ[ Log[ 3, n ] ], Print[ n ] ] ], {n, 1, 4* 10^6} ]

CROSSREFS

Subsequence of A006521.

Sequence in context: A116459 A185610 A185837 * A043407 A031691 A158220

Adjacent sequences: A016054 A016055 A016056 * A016058 A016059 A016060

KEYWORD

nonn

AUTHOR

Robert G. Wilson v

EXTENSIONS

Offset corrected by Amiram Eldar, Jul 04 2021

STATUS

approved