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A343086
a(n) is the smallest number that is the sum of n positive 4th powers in four ways.
4
5978882, 236674, 20995, 6626, 2925, 2925, 2854, 1620, 1621, 777, 778, 779, 780, 781, 782, 528, 529, 515, 516, 517, 518, 519, 520, 521, 522, 523, 524, 525, 526, 512, 513, 514, 515, 516, 517, 518, 519, 520, 521, 522, 523, 524, 525, 526, 527, 528, 529, 530, 531
OFFSET
3,1
COMMENTS
This is r(n,4,4) in Alter's notation.
LINKS
R. Alter, Computations and generalizations on a remark of Ramanujan, pp. 182-196 of "Analytic Number Theory (Philadelphia, 1980)", ed. M. I. Knopp, Lect. Notes Math., Vol. 899, 1981. See Table 12, page 194.
FORMULA
a(n) = n + 480 for n >= 32.
EXAMPLE
a(3) = 5978882 = 3^4 + 40^4 + 43^4 = 8^4 + 37^4 + 45^4 = 15^4 + 32^4 + 47^4 = 23^4 + 25^4 + 48^4.
a(4) = 236674 = 1^4 + 2^4 + 7^4 + 22^4 = 3^4 + 6^4 + 18^4 + 19^4 = 7^4 + 14^4 + 16^4 + 19^4 = 8^4 + 16^4 + 17^4 + 17^4.
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Apr 04 2021
STATUS
approved