OFFSET
0,2
COMMENTS
Number of rats in population after n years, starting with one rat at year 0 (see A016754 for more details).
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
O.g.f.: (1+222*x+169*x^2)/(1-x)^3 = 169/(1-x) - 560/(1-x)^2 + 392/(1-x)^3. - R. J. Mathar, Jan 31 2008
a(n) = A016754(7*n).
E.g.f.: (1 + 224*x + 196*x^2)*exp(x). - G. C. Greubel, Dec 24 2022
MATHEMATICA
(14*Range[0, 50]+1)^2 (* G. C. Greubel, Dec 24 2022 *)
PROG
(Magma) [(14*n+1)^2: n in [0..50]]; // Vincenzo Librandi, Sep 06 2011
(PARI) a(n)=(14*n+1)^2 \\ Charles R Greathouse IV, Jun 17 2017
(SageMath) [(14*n+1)^2 for n in range(51)] # G. C. Greubel, Dec 24 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Hans Isdahl, Jan 26 2008
STATUS
approved