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A120951
Numbers that are not the sum of 5 distinct nonzero squares.
3
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 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, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78, 80, 81, 83, 84, 85, 86, 89, 91, 92, 93, 96, 97, 98, 101, 102, 104, 105, 107, 108, 109, 112, 113, 116, 117, 119, 122, 124, 125, 128, 133, 136, 137, 140, 141, 149, 153, 161, 164, 173, 177, 182, 188, 189, 197, 203, 221, 224, 236, 245
OFFSET
1,2
COMMENTS
There are no other terms below 5000 and this list (of 124 terms) is probably complete. Is this known?
Thanks to R. K. Guy for supplying the references.
No others n < 10000. - T. D. Noe, Jul 23 2006
Bateman et al. prove that 245 is the last term. - T. D. Noe, Apr 03 2007
LINKS
Franklin T. Adams-Watters, Table of n, a(n) for n = 1..124
Paul T. Bateman, Adolf J. Hildebrand, and George B. Purdy, Sums of distinct squares, Acta Arithmetica 67 (1994), pp. 349-380.
E. Maitland Wright, The representation of a number as a sum of five or more squares, The Quarterly Journal of Mathematics, Volume os-4, Issue 1, 1933, Pages 37-51.
MATHEMATICA
nn=300; t=Table[0, {nn}]; lim=Floor[Sqrt[nn]]; sq=Table[i^2, {i, lim}]; Do[n=sq[[i1]]+sq[[i2]]+sq[[i3]]+sq[[i4]]+sq[[i5]]; If[n<=nn, t[[n]]++ ], {i1, lim}, {i2, i1+1, lim}, {i3, i2+1, lim}, {i4, i3+1, lim}, {i5, i4+1, lim}]; Flatten[Position[t, 0]] (* T. D. Noe, Jul 23 2006 *)
CROSSREFS
Cf. A004438.
Sequence in context: A247163 A376668 A357759 * A272554 A179797 A268200
KEYWORD
nonn,fini,full
AUTHOR
EXTENSIONS
Entry revised by N. J. A. Sloane, Jul 23 2006
STATUS
approved