login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A232731 Number of numbers that yield an n-digit number after Reverse and Add!. 4

%I

%S 4,50,450,4590,45405,454950,4544550,45454500,454495500,4545045000,

%T 45449955000,454500450000,4544999550000,45450004500000,

%U 454499995500000,4545000045000000,45449999955000000,454500000450000000,4544999999550000000,45450000004500000000

%N Number of numbers that yield an n-digit number after Reverse and Add!.

%C A190481 is the number of distinct n-digit numbers after Reverse and Add!.

%H Colin Barker, <a href="/A232731/b232731.txt">Table of n, a(n) for n = 1..1000</a>

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (10,10,-100).

%F a(1) = A232729(1), a(n) = A232729(n) + A232730(n-1), n > 1.

%F From _Colin Barker_, Mar 20 2017: (Start)

%F G.f.: x*(4 + 10*x - 90*x^2 - 10*x^3 + 5*x^4) / ((1 - 10*x)*(1 - 10*x^2)).

%F a(n) = 10*a(n-1) + 10*a(n-2) - 100*a(n-3) for n>5.

%F (End)

%t LinearRecurrence[{10,10,-100},{4,50,450,4590,45405},20] (* _Harvey P. Dale_, Sep 22 2017 *)

%o (PARI) Vec(x*(4 + 10*x - 90*x^2 - 10*x^3 + 5*x^4) / ((1 - 10*x)*(1 - 10*x^2)) + O(x^30)) \\ _Colin Barker_, Mar 20 2017

%Y Cf. A190481, A232729, A232730.

%K nonn,easy

%O 1,1

%A _Lars Blomberg_, Nov 29 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 8 08:08 EDT 2020. Contains 335520 sequences. (Running on oeis4.)