A100413 Numbers k such that k is reversal(k)-th even composite number (k is A004086(k)-th even composite number).

52, 592, 5992, 59992, 599992, 5999992, 59999992, 599999992, 5999999992, 59999999992, 599999999992, 5999999999992, 59999999999992, 599999999999992, 5999999999999992, 59999999999999992, 599999999999999992

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..500

Index entries for linear recurrences with constant coefficients, signature (11,-10).

Formula

a(n) = 6*10^n - 8.

a(n) = 2*(A086943(n) + 3). - Martin Ettl, Nov 08 2012

From Colin Barker, Oct 14 2014: (Start)

a(n) = 10*a(n-1) + a(n-2) - 10*a(n-3).

G.f.: 4*x*(13+5*x)/((1-x)*(1-10*x)). (End)

E.g.f.: 2 (1 - 4*exp(x) + 3*exp(10*x)). - G. C. Greubel, Apr 13 2023

Example

592 is in the sequence because 592 is the 295th even composite number.

Maple

A100413:=n->6*10^n-8; seq(A100413(n), n=1..20); # Wesley Ivan Hurt, Apr 06 2014

Mathematica

Table[6*10^n-8, {n, 20}]

Prog

(Maxima) A100413(n):=6*10^n-8$
makelist(A100413(n), n, 1, 17); /* Martin Ettl, Nov 08 2012 */
(PARI) Vec(4*x*(5*x+13)/((x-1)*(10*x-1)) + O(x^100)) \\ Colin Barker, Oct 14 2014
(Magma) [6*10^n -8: n in [1..20]]; // G. C. Greubel, Apr 13 2023
(SageMath) [6*10^n -8 for n in range(1, 21)] # G. C. Greubel, Apr 13 2023

Crossrefs

Cf. A004086, A086943, A100412.

Sequence in context: A000527 A294055 A285753 * A221272 A254137 A249712

Adjacent sequences: A100410 A100411 A100412 * A100414 A100415 A100416

Keyword

base,easy,nonn

Author

Farideh Firoozbakht, Dec 08 2004

Status

approved