cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A024803 Numbers that are the sum of 3 distinct nonzero squares, including repetitions.

Original entry on oeis.org

14, 21, 26, 29, 30, 35, 38, 41, 42, 45, 46, 49, 50, 53, 54, 56, 59, 61, 62, 62, 65, 66, 69, 69, 70, 74, 74, 75, 77, 77, 78, 81, 83, 84, 86, 86, 89, 89, 90, 90, 91, 93, 94, 94, 98, 98, 101, 101, 101, 104, 105, 105, 106, 107, 109, 110, 110, 110, 113, 114, 115, 116, 117
Offset: 1

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Numbers n = x^2 + y^2 + z^2, with 0
Records of 1,2,3 etc. repetitions are set by the numbers 14, 62, 101, 161, 206, 314, 341, 446, 689, 734, 854, 1106, 1154, 1286, 1454 etc.; see A025415. - R. J. Mathar, Mar 15 2007

Examples

			14 = 1^2 + 2^2 + 3^2.
62 = 1^2 + 5^2 + 6^2 = 2^2 + 3^2 + 7^2.
105 = 1^2 + 2^2 + 10^2 = 4^2 + 5^2 + 8^2.
122 = 3^2 + 7^2 + 8^2 = 4^2 + 5^2 + 9^2.
		

Crossrefs

Programs

  • Maple
    A024803 := proc(n) local a,x,y,z ; a := 0 ; for x from 1 to floor(sqrt(n)) do for y from x+1 to floor(sqrt(n-x^2)) do z := n-x^2-y^2 ; if issqr(z) then z := sqrt(z) ; if z>y and z>x then a := a+1 ; fi ; fi ; od ; od ; RETURN(a) ; end: for n from 1 to 200 do a := A024803(n) : for i from 1 to a do printf("%d ",n) ; od ; od : # R. J. Mathar, Mar 15 2007

Extensions

Zak Seidov pointed out that there were errors. These have now been corrected. - N. J. A. Sloane, Dec 05 2006
More terms from R. J. Mathar, Mar 15 2007