A123374 Primes p such that p^2 divides A086787(p+1).

2, 5, 17, 151

Offset

1,1

Comments

p divides A086787(p+1) for all prime p, except p=3.

Primes p such that p^2 divides (3 + Sum_{j=1..p+1} B_j) * p + 1, where B_j is the j-th Bernoulli number. [Max Alekseyev, Feb 19 2011]

Next term, if it exists, exceeds 320000. [Max Alekseyev, Mar 13 2011]

Links

Table of n, a(n) for n=1..4.

Example

a(1) = 2 because 2^2 divides A086787(3) = 56.
a(2) = 5 because 5^2 divides A086787(6) = 82200, but 3^2 does not divide A086787(4) = 494.

Crossrefs

Cf. A086787.

Sequence in context: A097980 A210525 A074046 * A067339 A309178 A096848

Adjacent sequences: A123371 A123372 A123373 * A123375 A123376 A123377

Keyword

hard,more,nonn

Author

Alexander Adamchuk, Oct 13 2006

Status

approved