OFFSET
0,2
REFERENCES
Albert H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
FORMULA
a(n) = C(n+5, 5)*(2n+3)/3.
G.f.: (1+3*x)/(1-x)^7.
From Amiram Eldar, Feb 15 2022: (Start)
Sum_{n>=0} 1/a(n) = 2161/28 - 768*log(2)/7.
Sum_{n>=0} (-1)^n/a(n) = 192*Pi/7 - 624*log(2)/7 - 657/28. (End)
MATHEMATICA
Nest[Accumulate, Range[1, 160, 4], 5] (* Vladimir Joseph Stephan Orlovsky, Jan 29 2012 *)
LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {1, 10, 49, 168, 462, 1092, 2310}, 40] (* Harvey P. Dale, Nov 08 2024 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Barry E. Williams, Dec 21 1999
EXTENSIONS
Corrected by T. D. Noe, Nov 09 2006
STATUS
approved