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 A005818 Numbers n that are primitive solutions to n^2 = a^2 + b^2 + c^2 (a,b,c > 0). 3
 3, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS These are the odd numbers excluding 1 and 5. Every term in A005767 is n*2^k for some k. LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 FORMULA G.f.: x*(-2*x^2 + x + 3)/(x - 1)^2. - Chai Wah Wu, Sep 14 2018 CROSSREFS Cf. A005767. Sequence in context: A180442 A165631 A245586 * A288444 A085820 A045572 Adjacent sequences:  A005815 A005816 A005817 * A005819 A005820 A005821 KEYWORD nonn AUTHOR N. J. A. Sloane, RALPH PETERSON (ralphp(AT)LIBRARY.NRL.NAVY.MIL) EXTENSIONS Name corrected by T. D. Noe, Nov 12 2010 STATUS approved

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Last modified October 23 16:53 EDT 2018. Contains 316529 sequences. (Running on oeis4.)