OFFSET
2,2
LINKS
Peter J. C. Moses, Table of n, a(n) for n = 2..301
FORMULA
If (2n-1, 2n+1) is a pair of twin primes, then a(n) = 2*n^2 - 2*n - 3.
MATHEMATICA
Table[Count[Table[Binomial[4*n^2-k-2, k-1]/k, {k, 3, 2*n^2-2}], _Integer], {n, 2, 30}] (* Peter J. C. Moses, Aug 17 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Aug 17 2013
EXTENSIONS
More terms from Peter J. C. Moses, Aug 17 2013
STATUS
approved