A156559 - OEIS

A156559

Primes of the form Sum_{k=1..m} (m^k mod (m-k+1)).

5, 7, 11, 31, 61, 73, 79, 149, 251, 257, 373, 439, 769, 839, 859, 1031, 1637, 1747, 3079, 3877, 3907, 4831, 5843, 6343, 7177, 7537, 8111, 8669, 9059, 10739, 11423, 12113, 12959, 12967, 13033, 13309, 13679, 13879, 16249, 16453, 21169, 21683, 23593, 23789, 26393

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..45.

MAPLE

P:=proc(i) local a, n; for n from 0 by 1 to i do a:=sum('(n^k mod (n-k+1))', 'k'=1..n); if isprime(a) then print(a); fi; od; end: P(500);

CROSSREFS

Cf. A156556, A156557, A156558.

Sequence in context: A259564 A308764 A288609 * A018426 A038976 A363673

Adjacent sequences: A156556 A156557 A156558 * A156560 A156561 A156562

KEYWORD

nonn,easy

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Feb 10 2009

EXTENSIONS

Offset changed to 1 by Jinyuan Wang, Aug 02 2021

STATUS

approved