OFFSET
1,2
LINKS
J. R. Griggs, Spanning subset sums for finite Abelian groups, Discrete Math., 229 (2001), 89-99.
FORMULA
For n=1, prime(1) is 2, and a(n) = 0.
PROG
(PARI) a(n) = floor(2*sqrt(prime(n)-2)); \\ Michel Marcus, Nov 26 2015
(PARI) a(n, p=prime(n))=sqrtint(4*p-8) \\ Charles R Greathouse IV, Jan 24 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Mar 17 2001
EXTENSIONS
Offset set to 1 by Michel Marcus, Nov 26 2015
STATUS
approved