

A112305


Let T(n) = A000073(n+1), n >= 1; a(n) = smallest k such that n divides T(k).


3



1, 3, 7, 4, 14, 7, 5, 7, 9, 19, 8, 7, 6, 12, 52, 15, 28, 12, 18, 31, 12, 8, 29, 7, 30, 39, 9, 12, 77, 52, 14, 15, 35, 28, 21, 12, 19, 28, 39, 31, 35, 12, 82, 8, 52, 55, 29, 64, 15, 52, 124, 39, 33, 35, 14, 12, 103, 123, 64, 52, 68, 60, 12, 15, 52, 35, 100, 28, 117
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OFFSET

1,2


COMMENTS

Brenner proves that every prime divides some tribonacci number T(n). The Mathematica program computes similar sequences for any nstep Fibonacci sequence.


REFERENCES

Ed Pegg, Jr., Posting to Sequence Fan mailing list, Nov 30, 2005


LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000
J. L. Brenner, Linear Recurrence Relations, Amer. Math. Monthly, Vol. 61 (1954), 171173.
Eric Weisstein's World of Mathematics, MathWorld: Tribonacci Number
Eric Weisstein's World of Mathematics, Tribonacci Number
Eric Weisstein's World of Mathematics, Tribonacci Number


EXAMPLE

T(1), T(2), T(3), T(4), ... are 1,1,2,4,7,13,24,...; a(3) = 7 because 3 first divides T(7) = A000073(8) = 24.


MATHEMATICA

n=3; Table[a=Join[{1}, Table[0, {n1}]]; k=0; While[k++; s=Mod[Plus@@a, i]; a=RotateLeft[a]; a[[n]]=s; s!=0]; k, {i, 100}] (* T. D. Noe *)


CROSSREFS

Cf. A000073.
Cf. A112312 (least k such that prime(n) divides T(k)).
Sequence in context: A016619 A066538 A216627 * A231396 A231463 A218616
Adjacent sequences: A112302 A112303 A112304 * A112306 A112307 A112308


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Nov 30 2005


STATUS

approved



