OFFSET
1,1
COMMENTS
LINKS
Zhi-Wei Sun, Table of n, a(n) for n = 1..140
Z.-W. Sun, Problems on combinatorial properties of primes, arXiv:1402.6641, 2014
EXAMPLE
a(1) = 5 since neither q(2) - 1 = 0 nor q(3) - 1 = 1 is prime, but q(5) - 1 = 2 is prime.
a(2) = 11 since q(7) - 1 = 4 is composite, but q(11) - 1 = 11 is prime.
MATHEMATICA
q[k_]:=q[k]=PrimeQ[PartitionsQ[Prime[k]]-1]
n=0; Do[If[q[k], n=n+1; Print[n, " ", Prime[k]]], {k, 1, 10^5}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Zhi-Wei Sun, Dec 29 2013
STATUS
approved