The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A086816 Smaller member of a twin prime pair with a triangular sum. 1
 17, 59, 137, 149, 1277, 1619, 2729, 4127, 6359, 11717, 13397, 17489, 20807, 23027, 28307, 29669, 51869, 61379, 69827, 73847, 78539, 92567, 97499, 115769, 138569, 166667, 176609, 193379, 200927, 258317, 304979, 430007, 500909, 518759, 536189 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS It is easily shown that all terms end in 7 or 9. LINKS Harvey P. Dale, Table of n, a(n) for n = 0..300 EXAMPLE 59 is a term because it is the smaller member of the twin prime pair (59,61) and 59 + 61 = 120 = 15*(15+1)/2. MATHEMATICA Transpose[Select[Partition[Prime[Range[45000]], 2, 1], #[[2]]-#[[1]]==2 && IntegerQ[(Sqrt[1+8Total[#]]-1)/2]&]][[1]] (* Harvey P. Dale, Dec 15 2011 *) CROSSREFS Cf. A000217, A001359. Sequence in context: A104165 A031391 A176783 * A243096 A221569 A179816 Adjacent sequences: A086813 A086814 A086815 * A086817 A086818 A086819 KEYWORD nonn AUTHOR Jason Earls, Aug 06 2003 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 May 30 14:34 EDT 2024. Contains 372968 sequences. (Running on oeis4.)