A180243 a(n) = number of ways in which the square of n can be expressed as the sum of a square, a cube and a fourth power.

0, 0, 0, 0, 2, 0, 1, 1, 3, 0, 0, 2, 0, 0, 0, 0, 2, 1, 2, 0, 3, 1, 2, 1, 2, 0, 0, 3, 0, 0, 1, 1, 4, 0, 2, 0, 2, 2, 2, 0, 1, 2, 0, 1, 4, 2, 3, 0, 0, 0, 4, 1, 4, 1, 5, 0, 2, 0, 2, 2, 3, 0, 1, 0, 5, 3, 2, 3, 3, 3, 2, 2, 5, 1, 5, 0, 4, 1, 1, 2, 5, 3, 1, 3, 1, 0, 4, 2, 3, 1, 3, 0, 3, 0, 5, 1, 3, 2, 2, 2, 1, 0, 4, 0, 12

Offset

1,5

Comments

The three terms of the sum and/or their bases can be the same.

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Example

a(9)=3 since 9^2 = 81 = 1^2+4^3+2^4 = 4^2+4^3+1^4 = 8^2+1^3+2^4.

Crossrefs

Cf. A180241, A180242.

Sequence in context: A316827 A286628 A378087 * A326728 A330944 A064918

Adjacent sequences: A180240 A180241 A180242 * A180244 A180245 A180246

Keyword

nonn

Author

Carmine Suriano, Aug 19 2010

Status

approved