A060361 a(n) = { Smallest prime > k } - k, where k = lcm(1..n).

1, 1, 1, 1, 1, 1, 1, 1, 13, 1, 1, 13, 13, 31, 31, 31, 23, 19, 19, 1, 1, 1, 1, 41, 41, 1, 1, 31, 31, 43, 43, 1, 41, 41, 41, 41, 41, 53, 53, 53, 53, 79, 79, 59, 59, 59, 59, 1, 1, 59, 59, 59, 59, 61, 61, 61, 61, 61, 61, 113, 113, 97, 97, 97, 179, 179, 179, 73

Offset: 0

Author

N. J. A. Sloane, Apr 01 2001

Keywords

• nonn

Programs

Mathematica

f[n_]:=Module[{lcm=LCM@@Range[n]},NextPrime[lcm]-lcm]; Join[{1}, Array[f,70]] (* Harvey P. Dale, May 20 2011 *)

PARI

a(n) = my(lc = lcm([1..n])); nextprime(lc+1) - lc; \\ Michel Marcus, Mar 18 2018