A256461 Smallest k such that A098550(n) + A098550(n+1) + ... + A098550(n+k) is prime, or -1 if there is no such k.

1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 4, 1, 0, 1, 1, 1, 18, 1, 5, 0, 0, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 9, 1, 1, 4, 1, 4, 1, 4, 0, 1, 1, 1, 1, 1, 16, 1, 0, 1, 1, 1, 7, 1, 1, 9, 1, 5, 0, 0, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 4, 4, 1, 7, 0, 1, 5, 1, 1, 4, 3, 1

Offset: 1

Author

Vladimir Shevelev, Mar 30 2015

Keywords

• nonn

Comments

Conjecture: a(n)>=0 for all n.

In contrast to this conjecture, for the sequence of the positive integers (A=A000027) there are infinitely many n for which A(n) + A(n+1) + ... + A(n+k) is composite for every k>=0 (cf. A089306, A077654).

Links

• Peter J. C. Moses, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A098550, A000027, A089306, A077654.

Extensions

More terms from Peter J. C. Moses, Mar 30 2015