This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A061722 a(n) = 10 * n^2 + 7. 3
 7, 17, 47, 97, 167, 257, 367, 497, 647, 817, 1007, 1217, 1447, 1697, 1967, 2257, 2567, 2897, 3247, 3617, 4007, 4417, 4847, 5297, 5767, 6257, 6767, 7297, 7847, 8417, 9007, 9617, 10247, 10897, 11567, 12257, 12967, 13697, 14447, 15217, 16007, 16817 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Initially this sequence is rich in primes. First 7 terms are all prime numbers. But the 8th term 491 is a composite number equal to 7 * 71. The first 28 terms are primes or semiprimes. - Kausthub Gudipati, Sep 25 2011 LINKS Harry J. Smith, Table of n, a(n) for n = 0..1000 T. Trotter, Jr, Trotter Numbers & Trotter Primes [Warning: As of March 2018 this site appears to have been hacked. Proceed with great caution. The original content should be retrieved from the Wayback machine and added here. - N. J. A. Sloane, Mar 29 2018] Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA a(n) = 10 * n^2 + 7. G.f.: ( -7+4*x-17*x^2 ) / (x-1)^3 . - R. J. Mathar, Feb 27 2015 PROG (PARI) { for (n=1, 1000, write("b061722.txt", n, " ", 10*n^2 + 7) ) } \\ Harry J. Smith, Jul 27 2009 CROSSREFS Cf. A061679, A195905. Sequence in context: A179030 A179031 A107178 * A195905 A104164 A192244 Adjacent sequences:  A061719 A061720 A061721 * A061723 A061724 A061725 KEYWORD easy,nonn AUTHOR Terrel Trotter, Jr., Jun 20 2001 EXTENSIONS Definition revised by Omar E. Pol, Aug 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 9 16:42 EST 2019. Contains 329879 sequences. (Running on oeis4.)