A102116 Iccanobirt numbers (6 of 15): a(n) = R(a(n-1)) + R(a(n-2)) + a(n-3), where R is the digit reversal function A004086.

0, 0, 1, 1, 2, 4, 7, 13, 42, 62, 63, 104, 499, 1458, 9639, 18409, 101308, 903221, 943819, 1141966, 8512981, 9527388, 11871383, 55668051, 62931854, 72771964, 148399704, 517843422, 705114520, 398159926, 1173206822, 3621090124, 6895084900

Offset: 0

Author

Jonathan Vos Post and Ray Chandler, Dec 30 2004

Keywords

• nonn
• base
• easy

Comments

Digit reversal variation of tribonacci numbers A000073.

Inspired by Iccanobif numbers: A001129, A014258-A014260.

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A102111-A102125.

Programs

Mathematica

R[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Clear[a];a[0]=0;a[1]=0;a[2]=1;a [n_]:=a[n]=R[a[n-1]]+R[a[n-2]]+a[n-3];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,FromDigits[Reverse[IntegerDigits[c]]]+ FromDigits[ Reverse[ IntegerDigits[b]]]+a}; Transpose[NestList[nxt,{0,0,1},40]][[1]] (* Harvey P. Dale, Oct 10 2014 *)

Formula

A004086(a(n)) = A102124(n).