login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A102124 Iccanobirt numbers (14 of 15): a(n) = R(R(a(n-1)) + R(a(n-2)) + a(n-3)), where R is the digit reversal function A004086. 8

%I #11 Dec 19 2015 00:24:48

%S 0,0,1,1,2,4,7,31,42,44,99,581,823,216,1251,6592,3964,98,47311,72451,

%T 99862,73698,789881,684873,171146,8359081,2855313,6626115,92901661,

%U 80528542,25591874,127303561,518156392,14745484,711014964,521206301

%N Iccanobirt numbers (14 of 15): a(n) = R(R(a(n-1)) + R(a(n-2)) + a(n-3)), where R is the digit reversal function A004086.

%C Digit reversal variation of tribonacci numbers A000073.

%C Inspired by Iccanobif numbers: A001129, A014258-A014260.

%H Alois P. Heinz, <a href="/A102124/b102124.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = A004086(A102116(n)).

%p R:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||n):

%p a:= proc(n) option remember; `if`(n<3, binomial(n, 2),

%p R(R(a(n-1)) + R(a(n-2)) + a(n-3)) )

%p end:

%p seq(a(n), n=0..50); # _Alois P. Heinz_, Jun 18 2014

%t R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[R[a[n-1]]+R[a[n-2]]+a[n-3]];Table[a[n], {n, 0, 40}]

%Y Cf. A102111-A102125.

%K nonn,base,easy

%O 0,5

%A _Jonathan Vos Post_ and _Ray Chandler_, Dec 30 2004

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 12 10:56 EDT 2024. Contains 375092 sequences. (Running on oeis4.)