OFFSET
0,1
COMMENTS
Numbers of the 8th column of positive numbers in the square array of nonnegative and polygonal numbers A139600.
REFERENCES
A. H. Beiler, Recreations in the Theory of Numbers, Dover, NY, 1964, p. 189. - From N. J. A. Sloane, Dec 01 2012
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = A057145(n+2,8).
a(n) = 2*a(n-1) - a(n-2); a(0)=8, a(1)=36. - Harvey P. Dale, Dec 14 2012
G.f.: 4*(2+5*x)/(x-1)^2. - R. J. Mathar, Jul 28 2016
From Elmo R. Oliveira, Apr 16 2024: (Start)
E.g.f.: 4*exp(x)*(2 + 7*x).
MATHEMATICA
Range[8, 7000, 28] (* Vladimir Joseph Stephan Orlovsky, Jul 13 2011 *)
LinearRecurrence[{2, -1}, {8, 36}, 50] (* or *) NestList[28+#&, 8, 50] (* Harvey P. Dale, Dec 14 2012 *)
PROG
(Magma) [4*(7*n + 2): n in [0..50]]; // Vincenzo Librandi, Jul 13 2011
(PARI) a(n)=28*n+8 \\ Charles R Greathouse IV, Oct 05 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Apr 27 2008
STATUS
approved