A057283 Numbers k such that k | 10^k + 9^k + 8^k + 7^k + 6^k + 5^k + 4^k + 3^k.

1, 2, 4, 10, 13, 38, 50, 169, 250, 1250, 2197, 2390, 3887, 5050, 6250, 18950, 25250, 25316, 28561, 31250, 49250, 88751, 126250, 129826, 156250, 217550, 371293, 377750, 510050, 584233, 593750, 631250, 651157, 781250, 1106750, 1318750, 1326250, 2550250, 3156250, 3741491, 3906250, 4085450, 4417550

Offset

1,2

Comments

The only primes in the sequence are 2 and 13. Are all terms except 1 divisible by 2 or 13? - Robert Israel, Feb 06 2018

Links

Table of n, a(n) for n=1..43.

Maple

select(n -> 10 &^ n + 9 &^ n + 8 &^ n + 7 &^ n + 6 &^ n + 5 &^ n + 4 &^ n + 3 &^ n mod n = 0 , [$1..10^6]); # Robert Israel, Feb 06 2018

Mathematica

Select[ Range[ 10^6 ], Mod[ PowerMod[ 10, #, # ] + PowerMod[ 9, #, # ] + PowerMod[ 8, #, # ] + PowerMod[ 7, #, # ] + PowerMod[ 6, #, # ] + PowerMod[ 5, #, # ] + PowerMod[ 4, #, # ] + PowerMod[ 3, #, # ], # ] == 0 & ]

Crossrefs

Contains A001022.

Sequence in context: A026224 A034233 A056718 * A308987 A107992 A139480

Adjacent sequences: A057280 A057281 A057282 * A057284 A057285 A057286

Keyword

nonn

Author

Robert G. Wilson v, Sep 22 2000

Extensions

More terms from Robert Israel, Feb 06 2018

Status

approved