OFFSET
1,8
FORMULA
a(n) = Sum_{i=1..floor((n-1)/2)} [Omega(n-2i) == 2], where Omega = A001222 and [] is the Iverson bracket.
MATHEMATICA
Table[Sum[KroneckerDelta[PrimeOmega[n - 2 i], 2], {i, Floor[(n - 1)/2]}], {n, 100}]
PROG
(PARI) a(n) = sum(i=1, (n-1)\2, bigomega(n-2*i)==2); \\ Michel Marcus, Apr 11 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Apr 10 2018
STATUS
approved