cp's OEIS Frontend

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.

%I A102124 #11 Dec 19 2015 00:24:48
%S A102124 0,0,1,1,2,4,7,31,42,44,99,581,823,216,1251,6592,3964,98,47311,72451,
%T A102124 99862,73698,789881,684873,171146,8359081,2855313,6626115,92901661,
%U A102124 80528542,25591874,127303561,518156392,14745484,711014964,521206301
%N 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.
%C A102124 Digit reversal variation of tribonacci numbers A000073.
%C A102124 Inspired by Iccanobif numbers: A001129, A014258-A014260.
%H A102124 Alois P. Heinz, <a href="/A102124/b102124.txt">Table of n, a(n) for n = 0..1000</a>
%F A102124 a(n) = A004086(A102116(n)).
%p A102124 R:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||n):
%p A102124 a:= proc(n) option remember; `if`(n<3, binomial(n, 2),
%p A102124        R(R(a(n-1)) + R(a(n-2)) + a(n-3)) )
%p A102124     end:
%p A102124 seq(a(n), n=0..50);  # _Alois P. Heinz_, Jun 18 2014
%t A102124 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 A102124 Cf. A102111-A102125.
%K A102124 nonn,base,easy
%O A102124 0,5
%A A102124 _Jonathan Vos Post_ and _Ray Chandler_, Dec 30 2004