OFFSET
0,5
COMMENTS
Conjecture: if n >= 23 then a(n)=2 if both (n-6) and (n-4) are prime, a(n)=1 if one of (n-6), (n-4) or (n-1) is prime, a(n)=0 otherwise
EXAMPLE
a(17)=2 since 17=2+3+5+7 and there are no other partitions of 17 into distinct primes, so the primes 2,3,5,7 and occur at least once but 11 and 13 do not. - Sean A. Irvine, Feb 15 2022
a(22)=1 since 22=2+7+13=2+3+17=5+17=3+19, so the primes 2,3,5,7,13,17 and 19 appear at least once but 11 does not.
CROSSREFS
KEYWORD
nonn
AUTHOR
Henry Bottomley, Apr 17 2000
EXTENSIONS
a(17) corrected and more terms from Sean A. Irvine, Feb 15 2022
STATUS
approved