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A199023 (6*11^n - 1) / 5. 6
1, 13, 145, 1597, 17569, 193261, 2125873, 23384605, 257230657, 2829537229, 31124909521, 342374004733, 3766114052065, 41427254572717, 455699800299889, 5012697803298781, 55139675836286593, 606536434199152525 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Sum of n-th row of triangle of powers of 11: 1; 1 11 1; 1 11 121 11 1; 1 11 121 1331 121 11 1; ... - Philippe Deléham, Feb 23 2014

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (12,-11).

FORMULA

a(n) = 11*a(n-1)+2.

a(n) = 12*a(n-1)-11*a(n-2), n>1.

G.f.: (1 + x)/(1 - 12*x + 11*x^2). - Vincenzo Librandi, Jan 04 2013

a(n) = Sum_{k=0..n} A112468(n,k)*12^k. - Philippe Deléham, Feb 23 2014

EXAMPLE

a(0) = 1;

a(1) = 1 + 11 + 1 = 13;

a(2) = 1 + 11 + 121 + 11 + 1 = 145;

a(3) = 1 + 11 + 121 + 1331 + 121 + 11 + 1 = 1597; etc. - Philippe Deléham, Feb 23 2014

MATHEMATICA

CoefficientList[Series[(1 + x)/(1 - 12*x + 11*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)

PROG

(Magma) [(6*11^n-1)/5 : n in [0..20]]

(PARI) a(n)=(6*11^n-1)/5 \\ Charles R Greathouse IV, Oct 07 2015

CROSSREFS

Cf. A112468, A112739.

Sequence in context: A038492 A270579 A297223 * A152585 A014881 A048442

Adjacent sequences: A199020 A199021 A199022 * A199024 A199025 A199026

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Nov 02 2011

STATUS

approved

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Last modified February 2 23:07 EST 2023. Contains 360024 sequences. (Running on oeis4.)