A107060 a(n) = smallest number m >=0 such that n*prime(n)-m is a prime.

0, 1, 2, 5, 2, 5, 6, 1, 8, 7, 4, 1, 10, 1, 4, 9, 6, 1, 14, 11, 2, 5, 2, 5, 2, 5, 4, 25, 24, 1, 6, 15, 2, 3, 6, 5, 2, 21, 22, 3, 6, 11, 4, 25, 2, 3, 10, 13, 4, 3, 16, 7, 10, 1, 28, 5, 2, 35, 4, 17, 6, 17, 8, 13, 4, 1, 6, 9, 14, 9, 6, 1, 8, 19, 14, 7, 6, 17, 12, 1, 2, 3, 2, 19, 2, 15, 16, 3, 6, 1, 6

Offset

1,3

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

f:= proc(n) local t, m;
  t:= n * ithprime(n);
  t - prevprime(t)
end proc:
f(1):= 0:
map(f, [$1..91]); # Robert Israel, Dec 24 2025

Mathematica

f[n_]:=Module[{pn=n Prime[n]}, pn-NextPrime[pn, -1]]; Join[{0}, Array[f, 100, 2]] (* Harvey P. Dale, Jul 21 2011 *)

Crossrefs

Cf. A107061.

Sequence in context: A177435 A087272 A299963 * A016589 A379574 A151572

Adjacent sequences: A107057 A107058 A107059 * A107061 A107062 A107063

Keyword

nonn

Author

Zak Seidov, May 10 2005

Status

approved