OFFSET
1,1
COMMENTS
All odd numbers > 1 occur in this sequence. For the subsequence of even terms, see A100319.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[Range[3, 100], CompositeQ[#-1] || CompositeQ[#+1] &] (* G. C. Greubel, Apr 25 2019 *)
PROG
(PARI) for(n=3, 100, if(isprime(n-1)+isprime(n+1)<=1, print1(n, ", ")))
(Magma) [n: n in [3..100] | not IsPrime(n-1) or not IsPrime(n+1) ]; // G. C. Greubel, Apr 25 2019
(Sage) [n for n in (3..100) if (is_prime(n-1) + is_prime(n+1) <= 1)] # G. C. Greubel, Apr 24 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Rick L. Shepherd, Nov 13 2004
STATUS
approved