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

Author

Amiram Eldar, Mar 09 2020

Keywords

• nonn

Examples

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

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.

Crossrefs

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

Programs

Mathematica

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

Formula

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