OFFSET
0,2
COMMENTS
It appears that a(n) does not exist for n in {30, 35, 45, 49, 57, 63, 67, 75, 77, 78, 82, 84, 85, 97, 100, 101, 104, 110, 112, 115, 116, 119, 123, 124, 125, 134, 136, 137, 140, 142, 143, 148, 149, 150, 151, 158, 159, 160, 162, 168, 170, 172, 174, 175, 176, 180, 183, 184, 185, 187, 188, 191, 198}; i.e., there is no integer whose number of representations is any of these values.
REFERENCES
E. Grosswald, Representations of Integers as Sums of Squares. Springer-Verlag, New York, 1985, p. 86, Theorem 1.
LINKS
D. H. Lehmer, On the Partition of Numbers into Squares, The American Mathematical Monthly, Vol. 55, No. 8, October 1948, pp. 476-481.
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert Price, Nov 26 2017
STATUS
approved