A102120 Iccanobirt numbers (10 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, 31, 24, 44, 711, 977, 8311, 1089, 4023, 53122, 51475, 33677, 412441, 945145, 6303211, 1027527, 8075903, 51363612, 74868455, 376085401, 68539284, 214889742, 927862936, 2360934421, 2982905123, 1968515515, 8282454457

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.

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, IntegerReverse[c + IntegerReverse[b] + a]}; NestList[nxt,{0,0,1},40][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 30 2017 *)

Formula

a(n) = A004086(A102112(n)).