A333173 a(n) = r_4(n^2 + 1), where r_4(k) is the number of ways of writing k as a sum of 4 squares (A000118).

8, 24, 48, 144, 144, 336, 304, 744, 672, 1008, 816, 1488, 1440, 2592, 1584, 2736, 2064, 4320, 3472, 4368, 3216, 6048, 4704, 7776, 4624, 7536, 5424, 10656, 7584, 10128, 7776, 12768, 10416, 15840, 10080, 14736, 10384, 19872, 14736, 18288, 12816, 20904, 16992, 28272

Offset

0,1

Links

Amiram Eldar, Table of n, a(n) for n = 0..10000

R. Sitaramachandrarao and P. V. Krishnaiah, On the sums Sigma_{n<=x} A(f(n)) and Sigma_{p<=x} A(f(p)), Journal of Number Theory, Vol. 23, No. 2 (1986), pp. 149-168.

Formula

a(n) = A000118(A002522(n)).

Example

a(0) = r_4(0^2 + 1) = r_4(1) = A000118(1) = 8.

Mathematica

Table[SquaresR[4, k^2 + 1], {k, 0, 100}]

Crossrefs

Cf. A000118, A002522 A193432, A193433, A333167, A333169.

Sequence in context: A342062 A319576 A028612 * A358036 A068857 A064225

Adjacent sequences: A333170 A333171 A333172 * A333174 A333175 A333176

Keyword

nonn

Author

Amiram Eldar, Mar 09 2020

Status

approved