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A342903
a(n) is the smallest number that is the sum of n positive squares in two ways.
10
50, 27, 28, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86
OFFSET
2,1
COMMENTS
This is r(n,2,2) 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 Eq. (15), page 188.
FORMULA
a(n) = n+15 for n >= 5.
EXAMPLE
a(2) = 50 = 1+49 = 25+25.
a(3) = 27 = 1+1+25 = 9+9+9.
a(5) = 20 = 1+1+1+1+16 = 4+4+4+4+4.
CROSSREFS
Sequence in context: A033370 A090691 A033980 * A207149 A207142 A244277
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 03 2021
STATUS
approved