A061679 Concatenation of n^3 and 7.

17, 87, 277, 647, 1257, 2167, 3437, 5127, 7297, 10007, 13317, 17287, 21977, 27447, 33757, 40967, 49137, 58327, 68597, 80007, 92617, 106487, 121677, 138247, 156257, 175767, 196837, 219527, 243897, 270007

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

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

Formula

a(n) = 10*n^3 + 7.

G.f.: -x*(-17 - 19*x - 31*x^2 + 7*x^3) / (x-1)^4. - R. J. Mathar, Feb 27 2015

Example

a(3) = 277 because we can say 10 * 3^3 + 7 = 10 * 27 + 7 = 270 + 7 = 277.

Mathematica

(10 Range[30]^3)+7 (* or *) LinearRecurrence[{4, -6, 4, -1}, {17, 87, 277, 647}, 30] (* Harvey P. Dale, Oct 20 2016 *)

Prog

(PARI) { for (n=1, 1000, write("b061679.txt", n, " ", 10*n^3 + 7) ) } \\ Harry J. Smith, Jul 26 2009

Crossrefs

Cf. A000578, A061722.

Sequence in context: A080770 A118863 A118533 * A271567 A231704 A033654

Adjacent sequences: A061676 A061677 A061678 * A061680 A061681 A061682

Keyword

base,easy,nonn

Author

Terrel Trotter, Jr., Jun 23 2001

Status

approved