This site is supported by donations to The OEIS Foundation.

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A117112 Primes expressible as the sum of two triangular numbers (including zero). 6
 2, 3, 7, 11, 13, 29, 31, 37, 43, 61, 67, 73, 79, 83, 97, 101, 127, 137, 139, 151, 157, 163, 181, 191, 193, 199, 211, 227, 241, 263, 277, 281, 307, 331, 353, 367, 373, 379, 389, 409, 421, 433, 443, 461, 463, 487, 499, 541, 571, 577, 587, 601, 619, 631, 659, 661 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS See A117048 for the primes that are the sum of two positive triangular numbers. The only difference is that the prime 3 occurs here. LINKS FORMULA A000040 intersect A020756. - Jonathan Vos Post, Apr 17 2006 EXAMPLE 2 = 1 + 1 3 = 0 + 3 7 = 1 + 6 and so on. MATHEMATICA tri = Table[n (n + 1)/2, {n, 0, 40}]; Select[Union[Flatten[Outer[Plus, tri, tri]]], # <= tri[[-1]]+1 && PrimeQ[#] &] (* T. D. Noe, Apr 07 2011 *) CROSSREFS Cf. A000217, A117048. Sequence in context: A091206 A038963 A167609 * A145032 A233414 A233863 Adjacent sequences:  A117109 A117110 A117111 * A117113 A117114 A117115 KEYWORD easy,nonn AUTHOR Greg Huber, Apr 18 2006 STATUS approved

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

Content is available under The OEIS End-User License Agreement .