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 A098375 (1/p)*abs(p*(p^(p-1)-1)*B(p-1)-1) when p runs through the primes and B(k) denotes the k-th Bernoulli's number. 0

%I

%S 1,1,21,2801,1964956409,5897061106093,345112805910366790769,

%T 5724003102153474225966281,5621496960287976955328551429580241,

%U 2417009997194019381479073094599560492013039757981

%N (1/p)*abs(p*(p^(p-1)-1)*B(p-1)-1) when p runs through the primes and B(k) denotes the k-th Bernoulli's number.

%C Conjecture: p is an odd prime iff p divides p*(p^(p-1)-1)*B(p-1)-1. Seems to be the equivalent (with integer moduli) to Agoh's conjecture (which involves rational moduli).

%H E. Weisstein, <a href="http://mathworld.wolfram.com/AgohsConjecture.html">Agoh's conjecture</a>.

%o (PARI) a(n)=(1/prime(n))*(prime(n)*(prime(n)^(prime(n)-1)-1)*bernfrac(prime(n)-1)-1)

%Y Cf. A089655.

%K nonn

%O 1,3

%A _Benoit Cloitre_, Oct 26 2004

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Last modified March 24 04:28 EDT 2023. Contains 361454 sequences. (Running on oeis4.)