A102121 Iccanobirt numbers (11 of 15): a(n) = R(a(n-1) + R(a(n-2)) + R(a(n-3))), where R is the digit reversal function A004086.

0, 0, 1, 1, 2, 4, 7, 31, 24, 44, 99, 581, 427, 117, 6201, 6367, 4018, 8621, 16342, 41752, 18376, 15486, 185801, 336123, 551315, 925189, 7799571, 5524929, 5346628, 6800461, 15116342, 36822052, 98232826, 48616741, 398264631, 406948574

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]]+R[a[n-3]]];Table[a[n], {n, 0, 40}]
nxt[{a_,b_,c_}]:={b,c,IntegerReverse[c+IntegerReverse[b]+IntegerReverse[a]]}; NestList[ nxt,{0,0,1},40][[;;,1]] (* Harvey P. Dale, Mar 23 2023 *)

Formula

a(n) = A004086(A102113(n)).