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A057490 Numbers n such that n divides 8^n + 7^n + 6^n + 5^n + 4^n + 3^n + 2^n. 0
1, 5, 7, 25, 35, 49, 125, 175, 245, 301, 343, 455, 625, 875, 1225, 1295, 1435, 1505, 1715, 1765, 2107, 2191, 2401, 3125, 4375, 6125, 7525, 8575, 10535, 11375, 12005, 12943, 14063, 14749, 15625, 16807, 21875, 22295, 30625, 35875, 37625, 42875, 52675, 60025, 64715, 70315, 73745, 78125, 80375, 84035, 90601, 93275 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Contains A003595.  The first term not in A003595 is 301.  Is 1 the only term not divisible by 5 or 7? - Robert Israel, Feb 22 2017

No term is divisible by 3. 5 and 7 are the only primes in this sequence. - Altug Alkan, Feb 23 2017

LINKS

Table of n, a(n) for n=1..52.

MAPLE

select(t -> add(i &^ t, i=2..8) mod t = 0, [$1..10^6]); # Robert Israel, Feb 22 2017

MATHEMATICA

Select[ Range[ 10^5 ], Mod[ PowerMod[ 8, #, # ] + PowerMod[ 7, #, # ] + PowerMod[ 6, #, # ] + PowerMod[ 5, #, # ] + PowerMod[ 4, #, # ] + PowerMod[ 3, #, # ] + PowerMod[ 2, #, # ], # ] == 0 & ]

CROSSREFS

Cf. A003595.

Sequence in context: A037374 A056717 A072370 * A057253 A003595 A018697

Adjacent sequences:  A057487 A057488 A057489 * A057491 A057492 A057493

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 22 2000

STATUS

approved

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Last modified April 6 08:06 EDT 2020. Contains 333267 sequences. (Running on oeis4.)