A102121 - OEIS

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

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OFFSET

0,5

COMMENTS

Digit reversal variation of tribonacci numbers A000073.

Inspired by Iccanobif numbers: A001129, A014258-A014260.

LINKS

Table of n, a(n) for n=0..35.

FORMULA

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

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 *)

CROSSREFS

Cf. A102111-A102125.

Sequence in context: A047904 A102118 A102119 * A102120 A280820 A280377

Adjacent sequences: A102118 A102119 A102120 * A102122 A102123 A102124

KEYWORD

nonn,base,easy

AUTHOR

Jonathan Vos Post and Ray Chandler, Dec 30 2004

STATUS

approved