The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A137366 Subsequence of A137365 where it is possible to choose p1, p2, p3 so that p1+p2+p3 = prime. 3
 1483, 5381, 6271, 7229, 9181, 11897, 13103, 13841, 14489, 17107, 20357, 25747, 26711, 27917, 30161, 30259, 31247, 32579, 36677, 36899, 36901, 42083, 48817, 54181, 55511, 55691, 56377, 57637, 64151, 66347, 69389, 75167, 76031, 76123 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 36161 is the first number that is in A137365 but not in the present sequence. See A138556. LINKS R. J. Mathar and Vincenzo Librandi, Table of n, a(n) for n = 1..350 (first 44 terms from R. J. Mathar) EXAMPLE 1483=3^3+5^3+11^3, 3+5+11=17; 7229=3^3+7^3+19^3, 3+7+19=29. MATHEMATICA Array[r, 99]; Array[y, 99]; For[i = 0, i < 10^2, r[i] = y[i] = 0; i++ ]; z = 4^2; n = 0; For[i1 = 1, i1 < z, a = Prime[i1]; a2 = a^3; For[i2 = i1 + 1, i2 < z, b = Prime[i2]; b2 = b^3; For[i3 = i2 + 1, i3 < z, c = Prime[i3]; c2 = c^3; p = a2 + b2 + c2; p3 = a + b + c; If[PrimeQ[p] && PrimeQ[p3], Print[a2, " + ", b2, " + ", c2, " = ", p, "; ", a, " + ", b, " + ", c, " = ", p3]; n++; r[n] = p]; i3++ ]; i2++ ]; i1++ ]; Sort[Array[r, 71]] lst = {}; Do[q = Prime@a; r = Prime@b; s = Prime@c; p = q^3 + r^3 + s^3; t = q + r + s; If[PrimeQ@p && PrimeQ@t, AppendTo[lst, p]], {a, 14}, {b, a - 1}, {c, b - 1}]; Take[Sort@lst, 35] (* Robert G. Wilson v, Apr 13 2008 *) CROSSREFS Cf. A137365, A138556. Sequence in context: A035864 A255087 A137365 * A045008 A327880 A257713 Adjacent sequences: A137363 A137364 A137365 * A137367 A137368 A137369 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, Apr 09 2008, Apr 14 2008 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 24 02:53 EDT 2024. Contains 373661 sequences. (Running on oeis4.)