A309222 a(0) = 6; thereafter a(n) = a(n-1) + prime(n) if prime(n) > a(n-1), otherwise a(n) = a(n-1) - prime(n).

6, 4, 1, 6, 13, 2, 15, 32, 13, 36, 7, 38, 1, 42, 85, 38, 91, 32, 93, 26, 97, 24, 103, 20, 109, 12, 113, 10, 117, 8, 121, 248, 117, 254, 115, 264, 113, 270, 107, 274, 101, 280, 99, 290, 97, 294, 95, 306, 83, 310, 81, 314, 75, 316, 65, 322, 59, 328, 57, 334, 53, 336, 43, 350, 39, 352

Offset

0,1

Comments

Hugo van der Sanden asks if this ever reaches 0. He finds that a(n) > 0 for n < 5*10^10. Probabilistic arguments suggest it will never reach 0.

References

Hugo van der Sanden, Posting to Sequence Fans Mailing List, Aug 28 2019

Links

N. J. A. Sloane, Table of n, a(n) for n = 0..20000

Crossrefs

If we start with 0 or 1 instead of 6 we get A008348, A022837.

Similar in spirit to A008344, and has a similar graph.

Sequence in context: A299998 A190405 A180659 * A324034 A365319 A343614

Adjacent sequences: A309219 A309220 A309221 * A309223 A309224 A309225

Keyword

nonn,look

Author

N. J. A. Sloane, Aug 29 2019

Status

approved