A024145 a(n) = 12^n - n^5.

1, 11, 112, 1485, 19712, 245707, 2978208, 35815001, 429948928, 5159721303, 61917264224, 743008209637, 8916100199424, 106993205007779, 1283918464011040, 15407021573826993, 184884258893987840

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 (18,-87,200,-255,186,-73,12).

Programs

Magma

[12^n-n^5: n in [0..20]]; // Vincenzo Librandi, Jul 01 2011

Mathematica

Table[12^n-n^5,{n,0,20}] (* or *) LinearRecurrence[ {18,-87,200,-255,186,-73,12},{1,11,112,1485,19712,245707,2978208},20] (* Harvey P. Dale, Jul 19 2011 *)

PARI

a(n)=12^n-n^5 \\ Charles R Greathouse IV, Jul 01 2011

Formula

a(n) = 18*a(n-1) - 87*a(n-2) + 200*a(n-3) - 255*a(n-4) + 186*a(n-5) - 73*a(n-6) + 12*a(n-7); a(0)=1, a(1)=11, a(2)=112, a(3)=1485, a(4)=19712, a(5)=245707, a(6)=2978208. - Harvey P. Dale, Jul 19 2011

G.f.: (-13*x^6 - 305*x^5 - 781*x^4 - 226*x^3 - x^2 + 7*x - 1)/((x-1)^6*(12*x-1)). - Harvey P. Dale, Jul 19 2011