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A294577 Numbers that are the sum of three squares (square 0 allowed) in exactly four ways. 7
81, 89, 101, 125, 129, 134, 149, 161, 162, 170, 171, 173, 189, 198, 201, 233, 241, 242, 243, 245, 246, 249, 250, 251, 254, 270, 274, 278, 285, 289, 294, 299, 324, 339, 349, 356, 361, 363, 370, 371, 378, 387, 390, 393, 395, 404, 406, 411, 417, 429, 433, 451 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

These are the numbers for which A000164(a(n)) = 4.

a(n) is the n-th largest number which has a representation as a sum of three integer squares (square 0 allowed), in exactly four ways, if neither the order of terms nor the signs of the numbers to be squared are taken into account. The multiplicity of a(n) with order and signs taken into account is A005875(a(n)).

This sequence is a proper subsequence of A000378.

LINKS

Robert Price, Table of n, a(n) for n = 1..1030

MATHEMATICA

Select[Range[0, 1000], Length[PowersRepresentations[#, 3, 2]] == 4 &]

CROSSREFS

Cf. A000164, A005875, A000378, A094942, A224442, A224443.

Sequence in context: A286898 A184044 A124968 * A044865 A162529 A243260

Adjacent sequences:  A294574 A294575 A294576 * A294578 A294579 A294580

KEYWORD

nonn

AUTHOR

Robert Price, Nov 02 2017

EXTENSIONS

Updated Mathematica program to Version 11. by Robert Price, Nov 01 2019

STATUS

approved

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Last modified November 18 19:59 EST 2019. Contains 329288 sequences. (Running on oeis4.)