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A248340 10^n - 5^n. 0
0, 5, 75, 875, 9375, 96875, 984375, 9921875, 99609375, 998046875, 9990234375, 99951171875, 999755859375, 9998779296875, 99993896484375, 999969482421875, 9999847412109375, 99999237060546875, 999996185302734375, 9999980926513671875 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..19.

Index entries for linear recurrences with constant coefficients, signature (15,-50).

FORMULA

G.f.: 5*x/((1-5*x)*(1-10*x)).

a(n)   = 15*a(n-1) - 50*a(n-2).

a(n)   = 5^n*(2^n-1) = A000351(n) * A000225(n) = A011557(n) - A000351(n).

a(n+1) = 5*A016164(n).

a(n)   = A016164(n) - A011557(n).

MATHEMATICA

Table[10^n - 5^n, {n, 0, 25}] (* or *) CoefficientList[Series[5 x/((1 - 5 x) (1 - 10 x)), {x, 0, 30}], x]

PROG

(MAGMA) [10^n-5^n: n in [0..30]];

CROSSREFS

Cf. sequences of the form k^n-5^n: A005062 (k=6), A121213 (k=7), A191468 (k=8), A191466 (k=9), this sequence (k=10), A139743 (k=11).

Cf. A016164.

Sequence in context: A105494 A030986 A284924 * A224088 A219462 A091882

Adjacent sequences:  A248337 A248338 A248339 * A248341 A248342 A248343

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Oct 05 2014

STATUS

approved

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Last modified August 8 16:16 EDT 2022. Contains 356015 sequences. (Running on oeis4.)