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A179015 Number of ways in which n^2 can be expressed as the sum of exactly five positive squares. 1
0, 0, 0, 1, 1, 1, 2, 5, 2, 6, 6, 9, 9, 15, 8, 25, 20, 21, 25, 39, 26, 46, 44, 57, 49, 71, 52, 102, 81, 81, 99, 145, 92, 156, 126, 164, 160, 204, 151, 247, 217, 236, 245, 326, 211, 357, 319, 381, 360, 416, 344, 518, 446, 476, 450, 670, 468, 675, 607, 661, 668, 825, 625 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

COMMENTS

As n goes to infinity the ratio of a(n)/a(n) of sequence A178898 (using all different squares) tends to 5/4.

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..740

FORMULA

Asymptotic behavior for large values of n is a(n) = n^2/2-47n/2+243.

a(n) = A025429(n^2). - R. J. Mathar, Jun 26 2010

a(n) = A065459(n) - A065458(n). - Alois P. Heinz, Oct 25 2018

MAPLE

a(8) = 5 since 64 can be expressed in five different ways as the sum of 5 squares (order is ignored): 8^2 = 7^2+3^2+2^2+1^2+1^2 = 6^2+5^2+1^2+1^2+1^2 = 6^2+4^2+2^2+2^2+2^2 = 6^2+3^2+3^2+3^2+1^2 = 5^2+5^2+3^2+1^2+1^2.

CROSSREFS

Cf. A000290, A178898.

Cf. A000132. - R. J. Mathar, Jun 26 2010

Cf. A065458, A065459.

Sequence in context: A198539 A121311 A242403 * A195621 A267090 A067948

Adjacent sequences:  A179012 A179013 A179014 * A179016 A179017 A179018

KEYWORD

nonn

AUTHOR

Carmine Suriano, Jun 24 2010

STATUS

approved

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Last modified September 24 07:01 EDT 2020. Contains 337317 sequences. (Running on oeis4.)