A024056 a(n) = 5^n - n^7.

1, 4, -103, -2062, -15759, -75000, -264311, -745418, -1706527, -2829844, -234375, 29340954, 208308817, 1157954608, 5998102121, 30346718750, 152319455169, 762529114452, 3814085045593, 19072592456386

Offset: 0

Author

N. J. A. Sloane

Keywords

• sign
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..500

Programs

Magma

[5^n-n^7: n in [0..30]]; // Vincenzo Librandi, Jul 03 2011

Formula

From Chai Wah Wu, Jan 26 2020: (Start)

a(n) = 13*a(n-1) - 68*a(n-2) + 196*a(n-3) - 350*a(n-4) + 406*a(n-5) - 308*a(n-6) + 148*a(n-7) - 41*a(n-8) + 5*a(n-9) for n > 8.

G.f.: (-6*x^8 - 591*x^7 - 5863*x^6 - 10833*x^5 - 3609*x^4 + 647*x^3 + 87*x^2 + 9*x - 1)/((x - 1)^8*(5*x - 1)). (End)