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

1,13

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.

Sequence in context: A290460 A334429 A295281 * A174699 A213027 A347618

Adjacent sequences: A256458 A256459 A256460 * A256462 A256463 A256464

Keyword

nonn

Author

Vladimir Shevelev, Mar 30 2015

Extensions

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

Status

approved