A065461 - OEIS

A065461

Number of inequivalent (ordered) solutions to n^2 = sum of 7 squares of integers >= 0.

1, 1, 2, 3, 4, 7, 10, 13, 16, 27, 36, 43, 58, 72, 99, 130, 146, 178, 254, 265, 342, 417, 507, 540, 726, 745, 975, 1092, 1289, 1338, 1845, 1751, 2246, 2447, 2948, 2852, 3932, 3638, 4728, 4868, 5778, 5618, 7659, 6887, 8891, 8887, 10825, 10109, 13712

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OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..500

EXAMPLE

a(4)=4 because 16 produces {0,0,0,0,0,0,4}, {0,0,0,2,2,2,2}, {0,0,1,1,1,2,3}, {1,1,1,1,2,2,2}.

MATHEMATICA

Table[Length[PowersRepresentations[n^2, 7, 2]], {n, 0, 50}] (* Harvey P. Dale, Sep 08 2020 *)

CROSSREFS

Cf. A063014, A016727.

Column k=7 of A255212.

Sequence in context: A309678 A279225 A073149 * A008824 A261616 A333615

Adjacent sequences: A065458 A065459 A065460 * A065462 A065463 A065464

KEYWORD

nonn

AUTHOR

Wouter Meeussen, Nov 18 2001

EXTENSIONS

a(0)=1 prepended by Alois P. Heinz, Feb 17 2015

Previous Mathematica program replaced by Harvey P. Dale, Sep 08 2020

STATUS

approved