A137789 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A137789

a(n) = 7^n - 6^n - 5^n - 4^n - 3^n - 2^n.

127, 4607, 50479, 446783, 3622207, 28040447, 211134799, 1561328063, 11403051487, 82538901887, 593482158319, 4245770823743, 30254894691967, 214923605948927, 1522969836817039, 10770185918341823, 76039637426447647, 536127667775741567

(list; graph; refs; listen; history; text; internal format)

OFFSET

4,1

COMMENTS

For n < 4, a(n) are negative and not entered here. - Michel Marcus, Nov 16 2013

LINKS

Table of n, a(n) for n=4..21.

Index entries for linear recurrences with constant coefficients, signature (27,-295,1665,-5104,8028,-5040).

FORMULA

G.f.: x^4*(488880*x^5-572076*x^4+231460*x^3-36445*x^2+1178*x+127)/((2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)*(7*x-1)). - Colin Barker, Nov 05 2012

a(n) = A000420(n) - A001553(n) + 1. - Michel Marcus, Nov 16 2013

MAPLE

A137789:=n->7^n-6^n-5^n-4^n-3^n-2^n; seq(A137789(n), n=4..50); # Wesley Ivan Hurt, Nov 15 2013

MATHEMATICA

Table[7^n - 6^n - 5^n - 4^n - 3^n - 2^n, {n, 4, 30}] (* Stefan Steinerberger, May 02 2008 *)

CROSSREFS

Sequence in context: A215611 A176357 A201071 * A268663 A005464 A160898

Adjacent sequences: A137786 A137787 A137788 * A137790 A137791 A137792

KEYWORD

nonn,easy

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 28 2008

EXTENSIONS

More terms from Stefan Steinerberger, May 02 2008

STATUS

approved