A001547 a(n) = (7*n+1)*(7*n+2)*(7*n+4).

8, 792, 4320, 12650, 27840, 51948, 87032, 135150, 198360, 278720, 378288, 499122, 643280, 812820, 1009800, 1236278, 1494312, 1785960, 2113280, 2478330, 2883168, 3329852, 3820440, 4356990, 4941560, 5576208, 6262992, 7003970, 7801200, 8656740, 9572648

Offset

0,1

Links

T. D. Noe, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (4, -6, 4, -1).

Formula

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4); a(0)=8, a(1)=792, a(2)=4320, a(3)=12650. - Harvey P. Dale, Jan 12 2013

From G. C. Greubel, May 19 2019: (Start)

G.f.: 2*(4 + 380*x + 600*x^2 + 45*x^3)/(1 - x)^4.

E.g.f.: (8 + 784*x + 1372*x^2 + 343*x^3)*exp(x). (End)

Mathematica

Times@@@Table[7n+{1, 2, 4}, {n, 0, 30}] (* or *) LinearRecurrence[{4, -6, 4, -1}, {8, 792, 4320, 12650}, 40] (* Harvey P. Dale, Jan 12 2013 *)

Prog

(PARI) a(n) = (7*n+1)*(7*n+2)*(7*n+4); \\ G. C. Greubel, May 19 2019
(Magma) [(7*n+1)*(7*n+2)*(7*n+4): n in [0..30]]; // G. C. Greubel, May 19 2019
(Sage) [(7*n+1)*(7*n+2)*(7*n+4) for n in (0..30)] # G. C. Greubel, May 19 2019
(GAP) List([0..30], n-> (7*n+1)*(7*n+2)*(7*n+4)) # G. C. Greubel, May 19 2019

Crossrefs

Sequence in context: A260032 A332178 A204464 * A168310 A220186 A054945

Adjacent sequences: A001544 A001545 A001546 * A001548 A001549 A001550

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved