A238901 a(n) is the smallest k, 1<=k<=(p_n-3)/2, such that sum{i=1,...,p_n-2k-1} 2^(i-1) Binomial(k-1+i, k)/p_n is prime; a(n)=0, if such k does not exist.

1, 1, 1, 6, 2, 5, 10, 1, 3, 11, 8, 13, 21, 5, 8, 29, 19, 19, 37, 0, 11, 11, 45, 42, 25, 11, 41, 7, 62, 39, 55, 70, 29, 60, 49, 24, 1, 0, 47, 73, 49, 78, 52, 11, 80, 80, 28, 32, 0, 92, 117, 112, 43, 102, 19, 97, 47, 38, 140, 51, 152, 44, 43, 141

Offset: 4

Author

Vladimir Shevelev, Mar 06 2014

Keywords

• nonn

Comments

Cf. comment in A238693.

Links

• Peter J. C. Moses, Table of n, a(n) for n = 4..1003
• V. Shevelev, Banach matchboxes problem and a congruence for primes, arXiv:1110.5686

Crossrefs

Cf. A238693, A238697, A238698, A238700.

Extensions

More terms from Peter J. C. Moses, Mar 06 2014