A248338 10^n - 4^n.

0, 6, 84, 936, 9744, 98976, 995904, 9983616, 99934464, 999737856, 9998951424, 99995805696, 999983222784, 9999932891136, 99999731564544, 999998926258176, 9999995705032704, 99999982820130816, 999999931280523264, 9999999725122093056, 99999998900488372224

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Index entries for linear recurrences with constant coefficients, signature (14,-40).

Formula

G.f.: 6*x/((1-4*x)*(1-10*x)).

a(n) = 14*a(n-1) - 40*a(n-2).

a(n) = 2^n*(5^n-2^n) = A000079(n) * A005057(n) = A011557(n) - A000302(n).

a(n+1) = 6*A016157(n). [Bruno Berselli, Oct 05 2014]

Mathematica

Table[10^n - 4^n, {n, 0, 25}] (* or *) CoefficientList[Series[(6 x) / ((1 - 4 x) (1 - 10 x)), {x, 0, 30}], x]

Prog

(Magma) [10^n-4^n: n in [0..30]];
(PARI) vector(20, n, 10^(n-1)-4^(n-1)) \\ Derek Orr, Oct 05 2014

Crossrefs

Cf. similar sequences listed in A248337.

Cf. A016157.

Sequence in context: A098982 A229455 A212701 * A144514 A244284 A011945

Adjacent sequences: A248335 A248336 A248337 * A248339 A248340 A248341

Keyword

nonn,easy

Author

Vincenzo Librandi, Oct 05 2014

Status

approved