A301295 Smallest distance from n to a prime power (as defined in A000961).

0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 2, 3, 2, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 3, 2, 1, 0, 1, 0, 1, 0, 1, 2, 3, 2, 1, 0, 1, 2, 3, 4, 3, 2, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2

Offset

1,21

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Prog

(PARI) A301295(n) = if(1==n, 0, my(k=0); while(!isprimepower(n+k) && !isprimepower(n-k), k++); (k)); \\ Antti Karttunen, Sep 25 2018

Crossrefs

There are four different sequences which may legitimately be called "prime powers": A000961 (p^k, k >= 0), A246655 (p^k, k >= 1), A246547 (p^k, k >= 2), A025475 (p^k, k=0 and k >= 2).

Identical to A080732 except here a(1)=0.

Cf. also A051699, A175851.

Sequence in context: A338757 A080733 A080732 * A215036 A294448 A088568

Adjacent sequences: A301292 A301293 A301294 * A301296 A301297 A301298

Keyword

nonn,look

Author

N. J. A. Sloane, Mar 24 2018

Extensions

More terms from Antti Karttunen, Sep 25 2018

Status

approved