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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A171140 Numbers k such that 6*k + 7 = p^2 (p=prime). 1
 3, 7, 19, 27, 47, 59, 87, 139, 159, 227, 279, 307, 367, 467, 579, 619, 747, 839, 887, 1039, 1147, 1319, 1567, 1699, 1767, 1907, 1979, 2127, 2687, 2859, 3127, 3219, 3699, 3799, 4107, 4427, 4647, 4987, 5339, 5459, 6079, 6207, 6467, 6599, 7419, 8287, 8587 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Subsequence of A164097. - R. J. Mathar, Jul 06 2010 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 EXAMPLE 6*3 + 7 = 5^2, so 3 is a term; 6*7 + 7 = 7^2, so 7 is a term; 6*19 + 7 = 11^2, so 19 is a term; 6*27 + 7 = 13^2, so 27 is a term. MATHEMATICA Select[Range[10000], PrimeQ[Sqrt[6 # + 7]]&] (* Vincenzo Librandi, Apr 06 2013 *) PROG (Magma) [(p^2-7)/6: p in PrimesInInterval(4, 250)]; // Vincenzo Librandi, Apr 06 2013 CROSSREFS Cf. A164097. Sequence in context: A203319 A366171 A164097 * A186452 A016046 A239219 Adjacent sequences: A171137 A171138 A171139 * A171141 A171142 A171143 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Dec 04 2009 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 November 30 23:40 EST 2023. Contains 367464 sequences. (Running on oeis4.)