OFFSET
0,2
REFERENCES
A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 189, 194-196.
P. Ribenhoim, The Little Book of Big Primes, Springer-Verlag, N.Y., 1991, p. 53.
LINKS
Index entries for linear recurrences with constant coefficients, signature (6,-12,10,-3).
FORMULA
a(n) = ((3^(n+3)) - (2*(n^2) + 12n + 19))/8.
a(n) = 3a(n-1)+C(n+2,2); a(0)=1.
a(n) = sum{k=0..n, binomial(n+3, k+3)2^k}. - Paul Barry, Aug 20 2004
From Colin Barker, Dec 18 2012: (Start)
a(n) = 6*a(n-1) - 12*a(n-2) + 10*a(n-3) - 3*a(n-4).
G.f.: 1/((x-1)^3*(3*x-1)). (End)
MATHEMATICA
LinearRecurrence[{6, -12, 10, -3}, {1, 6, 24, 82}, 40] (* Harvey P. Dale, Sep 05 2013 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Barry E. Williams, Jan 23 2000
STATUS
approved