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A156376
a(n) = 30*n + 19.
2
19, 49, 79, 109, 139, 169, 199, 229, 259, 289, 319, 349, 379, 409, 439, 469, 499, 529, 559, 589, 619, 649, 679, 709, 739, 769, 799, 829, 859, 889, 919, 949, 979, 1009, 1039, 1069, 1099, 1129, 1159, 1189, 1219, 1249, 1279, 1309, 1339, 1369, 1399, 1429, 1459
OFFSET
0,1
FORMULA
a(n) = 2*a(n-1) - a(n-2).
G.f.: (19+11*x)/(x-1)^2.
Sum_{n>=0} a(n)/(16*(n+1)^3*(2n+1)*binomial(2n+1,n)^2) = zeta(3). - Daniel Suteu, Oct 31 2017
MATHEMATICA
Range[19, 7000, 30] (* Vladimir Joseph Stephan Orlovsky, Jul 13 2011 *)
LinearRecurrence[{2, -1}, {19, 49}, 50] (* Vincenzo Librandi, Mar 01 2012 *)
PROG
(Magma) I:=[19, 49]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]]; // Vincenzo Librandi, Mar 01 2012
CROSSREFS
Sequence in context: A165672 A136686 A130413 * A063306 A267572 A349554
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Aug 12 2009
EXTENSIONS
Offset corrected by R. J. Mathar, Oct 12 2009
STATUS
approved