OFFSET
0,1
COMMENTS
(a(n-1))^2 + a(n) is a square. - Vincenzo Librandi, Aug 08 2010
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Gennady Eremin, Partitioning the set of natural numbers into Mersenne trees and into arithmetic progressions; Natural Matrix and Linnik's constant, arXiv:2405.16143 [math.CO], 2024. See pp. 3-4.
Index entries for linear recurrences with constant coefficients, signature (3,-2).
FORMULA
a(n) = 2*a(n-1) + 1.
G.f.: ( 10-9*x ) / ( (2*x-1)*(x-1) ). - R. J. Mathar, Oct 22 2011
MATHEMATICA
NestList[2#+1&, 10, 30] (* or *) LinearRecurrence[{3, -2}, {10, 21}, 30] (* Harvey P. Dale, Nov 25 2013 *)
PROG
(PARI) a(n) = 11*2^n - 1 \\ Michel Marcus, Jul 15 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Marco Matosic, Jul 29 2003
STATUS
approved