A024120 a(n) = 10^n - n^6.

1, 9, 36, 271, 5904, 84375, 953344, 9882351, 99737856, 999468559, 9999000000, 99998228439, 999997014016, 9999995173191, 99999992470464, 999999988609375, 9999999983222784, 99999999975862431, 999999999965987776

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..300
• Index entries for linear recurrences with constant coefficients, signature (17,-91,245,-385,371,-217,71,-10)

Crossrefs

Cf. A001014 (n^6), A011557 (10^n).

Programs

Magma

[10^n-n^6: n in [0..20]]; // Vincenzo Librandi, Jun 30 2011

Mathematica

Table[10^n-n^6,{n,0,30}] (* or *) LinearRecurrence[ {17,-91,245,-385,371,-217,71,-10},{1,9,36,271,5904,84375,953344,9882351},30] (* Harvey P. Dale, Oct 09 2012 *)

PARI

a(n) = 10^n-n^6; \\ Altug Alkan, Oct 04 2018

Formula

G.f.: ( 1 - 8*x - 26*x^2 + 233*x^3 + 2753*x^4 + 2942*x^5 + 576*x^6 + 9*x^7 ) / ( (10*x-1)*(x-1)^7 ). - R. J. Mathar, Jun 30 2011