A102122 Iccanobirt numbers (12 of 15): a(n) = R(R(a(n-1)) + a(n-2) + a(n-3)), where R is the digit reversal function A004086.

0, 0, 1, 1, 2, 4, 7, 31, 42, 26, 531, 302, 67, 909, 8721, 4522, 48811, 72152, 6487, 908821, 844702, 6572211, 9726782, 29139201, 58129562, 86185456, 139627251, 949140792, 656458225, 9962261161, 6171227123, 20114953831, 68392496992

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[R[a[n-1]]+a[n-2]+a[n-3]];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,IntegerReverse[IntegerReverse[c]+b+a]}; NestList[nxt,{0,0,1},40][[;;,1]] (* Harvey P. Dale, Sep 10 2024 *)

Formula

a(n) = A004086(A102114(n)).