login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A036704
a(n)=number of Gaussian integers z=a+bi satisfying |z|<=n+1/2.
5
1, 9, 21, 37, 69, 97, 137, 177, 225, 293, 349, 421, 489, 577, 665, 749, 861, 973, 1085, 1201, 1313, 1457, 1597, 1741, 1885, 2053, 2217, 2377, 2561, 2733, 2933, 3125, 3313, 3521, 3745, 3969, 4197, 4421, 4669, 4905, 5169, 5417
OFFSET
0,2
FORMULA
a(n) = A057655(n^2+n). - Robert Israel, Sep 29 2014
CROSSREFS
Cf. A057655.
Sequence in context: A140673 A186294 A059993 * A338911 A107890 A110209
KEYWORD
nonn
STATUS
approved