A079728 - OEIS

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A079728

sum(k=0,p,binomial(2*k,k)) (mod p) where p runs through the primes.

1, 2, 1, 3, 1, 3, 1, 3, 1, 1, 3, 3, 1, 3, 1, 1, 1, 3, 3, 1, 3, 3, 1, 1, 3, 1, 3, 1, 3, 1, 3, 1, 1, 3, 1, 3, 3, 3, 1, 1, 1, 3, 1, 3, 1, 3, 3, 3, 1, 3, 1, 1, 3, 1, 1, 1, 1, 3, 3, 1, 3, 1, 3, 1, 3, 1, 3, 3, 1, 3, 1, 1, 3, 3, 3, 1, 1, 3, 1, 3, 1

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..81.

FORMULA

a(1) = 1 a(2) = 2 a(prime(n)) = 3 if prime(n) is in A002476 a(prime(n)) = 1 otherwise (i.e. if prime(n) is in A003627).

PROG

(PARI) a(n) = sum(k=0, prime(n), binomial(2*k, k))%prime(n)

CROSSREFS

Cf. A002476, A003627, A006134.

Sequence in context: A328050 A335620 A176982 * A181801 A029244 A067513

Adjacent sequences: A079725 A079726 A079727 * A079729 A079730 A079731

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Feb 17 2003

STATUS

approved