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
KEYWORD
easy,nonn
AUTHOR
Terrel Trotter, Jr., Jun 20 2001
EXTENSIONS
Definition revised by Omar E. Pol, Aug 04 2009
STATUS
approved