login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Brenner proves that every prime divides some tribonacci number T(n). The Mathematica program computes similar sequences for any n-step 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), 171-173.

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, {n-1}]]; 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 28 17:37 EDT 2020. Contains 334684 sequences. (Running on oeis4.)