OFFSET
0,2
COMMENTS
Essentially the same as A285786, except for the offset and initial values.
FORMULA
EXAMPLE
a(0) = 0 because between 2*0^2 = 0 and 2*1^2 = 2, there are no (odd) primes.
a(1) = 3 because between 2*1^2 = 2 and 2*2^2 = 8 there are the 3 (odd) primes 3, 5 and 7.
a(2) = 3 because between 2*2^2 = 8 and 2*3^2 = 18] there are the 3 primes 11, 13 and 17.
PROG
(PARI) a(n)=primepi(2*(n+1)^2-1)-primepi(2*n^2)
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, May 02 2017
STATUS
approved