The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A169830

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A169830

Numbers n such that 2*reverse(n) - n = 1.
(history; published version)

#32 by N. J. A. Sloane at Thu Aug 13 14:02:28 EDT 2020

LINKS

Erich Friedman, <a href="httphttps://www2erich-friedman.stetsongithub.edu/~efriedmaio/numbers.html">What's Special About This Number?</a> (See entry 73.)

Discussion

Thu Aug 13

14:02

OEIS Server: https://oeis.org/edit/global/2866

#31 by Bruno Berselli at Mon Feb 13 03:50:58 EST 2017

STATUS

proposed

approved

#30 by Michael De Vlieger at Sun Feb 12 12:55:16 EST 2017

STATUS

editing

proposed

#29 by Michael De Vlieger at Sun Feb 12 12:55:11 EST 2017

MATHEMATICA

Rest@ CoefficientList[Series[x (1 + 62 x)/((1 - x) (1 - 10 x)), {x, 0, 20}], x] (* or *)

Table[If[n == 1, 1, FromDigits@ Join[{7}, ConstantArray[9, n - 2], {3}]], {n, 20}] (* or *)

LinearRecurrence[{11, -10}, {1, 73}, 20] (* Michael De Vlieger, Feb 12 2017 *)

STATUS

proposed

editing

#28 by Michel Marcus at Sun Feb 12 11:03:12 EST 2017

STATUS

editing

proposed

#27 by Michel Marcus at Sun Feb 12 11:03:00 EST 2017

PROG

(PARI) isok(n) = 2*fromdigits(Vecrev(digits(n))) - n == 1; \\ Michel Marcus, Feb 12 2017

STATUS

proposed

editing

#26 by Matthew House at Sun Feb 12 06:52:31 EST 2017

STATUS

editing

proposed

#25 by Matthew House at Sun Feb 12 06:51:23 EST 2017

LINKS

Matthew House, <a href="/A169830/b169830.txt">Table of n, a(n) for n = 1..996</a>

<a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (11,-10).

FORMULA

From Matthew House, Feb 12 2017: (Start)

G.f.: x*(1+62*x)/((1-x)*(1-10*x)).

a(n) = 11*a(n-1) - 10*a(n-2). (End)

STATUS

approved

editing

#24 by Alois P. Heinz at Sat Jul 25 15:52:19 EDT 2015

STATUS

proposed

approved

#23 by Jon E. Schoenfield at Sat Jul 25 15:23:12 EDT 2015

STATUS

editing

proposed