1,2

Table of n, a(n) for n=1..66.

J. R. Griggs, Spanning subset sums for finite Abelian groups, Discrete Math., 229 (2001), 89-99.

For n=1, prime(1) is 2, and a(n) = 0.

(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

Cf. A060018.

Sequence in context: A075527 A154257 A297351 * A093451 A106006 A050460

Adjacent sequences: A060016 A060017 A060018 * A060020 A060021 A060022

nonn

N. J. A. Sloane, Mar 17 2001

Offset set to 1 by Michel Marcus, Nov 26 2015

approved