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 A007520 Primes == 3 (mod 8). (Formerly M2882) 37
 3, 11, 19, 43, 59, 67, 83, 107, 131, 139, 163, 179, 211, 227, 251, 283, 307, 331, 347, 379, 419, 443, 467, 491, 499, 523, 547, 563, 571, 587, 619, 643, 659, 683, 691, 739, 787, 811, 827, 859, 883, 907, 947, 971, 1019, 1051, 1091, 1123, 1163, 1171, 1187 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes of the form 3x^2 + 2xy + 3y^2 with x and y in Z. - T. D. Noe, May 07 2005 Also, primes of the form X^2 + 2Y^2, X=|x-y|, Y=x+y. - Zak Seidov, Dec 06 2011 Each term is the sum of no fewer than three positive squares. - T. D. Noe, Nov 15 2010 Smallest terms expressible as sum of three distinct positive squares: 59 = 1^2 + 3^2 + 7^2, 83 = 3^2 + 5^2 + 7^2, 107, 131, 139, 179, 211, 227, 251, 283, 307. - Zak Seidov, Dec 06 2011 Except for the first term it appears that the terms of the sequence are also primes of the form 2k+1 such that 3*(2k+1) divides 2^k+1. - Hilko Koning, Dec 06 2019 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Ray Chandler, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe) M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy]. Alexander Kalmynin, On Novák numbers, arXiv:1611.00417 [math.NT], 2016. See P0 in Theorem 7 p. 11. MAPLE A007520 := proc(n)     option remember;     local a;     if n = 1 then         return 3;     end if;     a := nextprime(procname(n-1)) ;     while modp(a, 8) <> 3 do         a := nextprime(a) ;     end do:     a ; end proc: seq(A007520(n), n=1..30) ; # R. J. Mathar, Apr 07 2017 MATHEMATICA lst={}; Do[p=8*n+3; If[PrimeQ[p], AppendTo[lst, p]], {n, 0, 10^3}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 22 2008 *) p=3; k=0; nn=1000; Reap[While[k

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Last modified July 4 02:56 EDT 2020. Contains 335436 sequences. (Running on oeis4.)