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A024079 a(n) = 7^n - n^4. 2
1, 6, 33, 262, 2145, 16182, 116353, 821142, 5760705, 40347046, 282465249, 1977312102, 13841266465, 96888981846, 678223034433, 4747561459318, 33232930504065, 232630513903686, 1628413597805473, 11398895185242822 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (12,-45,80,-75,36,-7).

FORMULA

From Chai Wah Wu, May 13 2017: (Start)

a(n) = 12*a(n-1) - 45*a(n-2) + 80*a(n-3) - 75*a(n-4) + 36*a(n-5) - 7*a(n-6) for n > 5.

G.f.: (6*x^5 + 81*x^4 + 56*x^3 + 6*x^2 - 6*x + 1)/((x - 1)^5*(7*x - 1)). (End)

MATHEMATICA

Array[7^# - #^4 &, 20, 0] (* or *)

CoefficientList[Series[(6 x^5 + 81 x^4 + 56 x^3 + 6 x^2 - 6 x + 1)/((x - 1)^5*(7 x - 1)), {x, 0, 19}], x] (* Michael De Vlieger, May 13 2017 *)

LinearRecurrence[{12, -45, 80, -75, 36, -7}, {1, 6, 33, 262, 2145, 16182}, 20] (* Harvey P. Dale, Feb 02 2020 *)

PROG

(MAGMA) [7^n-n^4: n in [0..25]]; // Vincenzo Librandi, Jul 03 2011

CROSSREFS

Sequence in context: A320420 A215707 A137970 * A228640 A228618 A118094

Adjacent sequences:  A024076 A024077 A024078 * A024080 A024081 A024082

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified November 28 13:47 EST 2021. Contains 349413 sequences. (Running on oeis4.)