OFFSET
1,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = A056929(2n). - M. F. Hasler, Dec 26 2007
EXAMPLE
a(1)=0 because 4 - (3 + 5)/2 = 0
a(2)=1 because 16 - (13 + 17)/2 = 1
a(3)=2 because 36 - (31 + 37)/2 = 2
a(4)=0 because 64 - (61 + 67)/2 = 0
a(5)=1 because 100 - (97 + 101)/2 = 1
MATHEMATICA
Table[n^2-(Prime[PrimePi[n^2]]+Prime[PrimePi[n^2]+1])/2, {n, 2, 200, 2}] (* Zak Seidov *)
diff4[n_]:=Module[{x=4n^2}, x-(NextPrime[x]+NextPrime[x, -1])/2]; Array[ diff4, 90] (* Harvey P. Dale, Aug 31 2017 *)
PROG
(PARI) A133450(n)=4*n^2-(precprime(4*n^2)+nextprime(4*n^2))/2 \\ M. F. Hasler, Dec 26 2007
CROSSREFS
KEYWORD
sign
AUTHOR
Alexander R. Povolotsky, Dec 22 2007
EXTENSIONS
Corrected and extended by Zak Seidov, Dec 23 2007
Edited by N. J. A. Sloane, Dec 23 2007
STATUS
approved