

A000414


Numbers that are the sum of 4 nonzero squares.


11



4, 7, 10, 12, 13, 15, 16, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 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
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OFFSET

1,1


LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000
Index entries for sequences related to sums of squares


FORMULA

a(n) = n + O(log n).  Charles R Greathouse IV, Sep 03 2014


MATHEMATICA

q=16; lst={}; Do[Do[Do[Do[z=a^2+b^2+c^2+d^2; If[z<=(q^2)+3, AppendTo[lst, z]], {d, q}], {c, q}], {b, q}], {a, q}]; Union@lst (*Vladimir Joseph Stephan Orlovsky, Feb 07 2010 *)


PROG

(PARI) is(n)=my(k=if(n, n/4^valuation(n, 4), 2)); k!=2 && k!=6 && k!=14 && !setsearch([0, 1, 3, 5, 9, 11, 17, 29, 41], n) \\ Charles R Greathouse IV, Sep 03 2014


CROSSREFS

Cf. A000534 (complement).
Sequence in context: A237707 A211642 A127958 * A025357 A222949 A144020
Adjacent sequences: A000411 A000412 A000413 * A000415 A000416 A000417


KEYWORD

nonn


AUTHOR

N. J. A. Sloane and J. H. Conway


EXTENSIONS

corrected 6/95


STATUS

approved



