A186191 First digit of tetranacci numbers A000288.

1, 1, 1, 1, 4, 7, 1, 2, 4, 9, 1, 3, 6, 1, 2, 4, 9, 1, 3, 6, 1, 2, 4, 9, 1, 3, 6, 1, 2, 4, 9, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 8, 1, 3, 6, 1, 2, 4, 8, 1, 3, 5, 1, 2, 4, 8, 1, 3, 5, 1, 2, 4, 8, 1, 3, 5

Offset

0,5

Comments

Sequence obeys Benford law about distribution of first digits in a sequence: P(n)=Log(1+1/n).

Links

Table of n, a(n) for n=0..103.

Index entries for sequences related to Benford's law

Example

a(9)=9 since Tetra(9)=94.

Mathematica

t = {1, 1, 1, 1}; Do[AppendTo[t, t[[-1]] + t[[-2]] + t[[-3]] + t[[-4]]], {100}]; Table[IntegerDigits[i][[1]], {i, t}]
IntegerDigits[#][[1]]&/@LinearRecurrence[{1, 1, 1, 1}, {1, 1, 1, 1}, 120] (* Harvey P. Dale, Nov 08 2024 *)

Crossrefs

Cf. A000288.

Sequence in context: A188735 A254338 A197723 * A256507 A123734 A011519

Adjacent sequences: A186188 A186189 A186190 * A186192 A186193 A186194

Keyword

nonn,base

Author

Carmine Suriano, Feb 14 2011

Extensions

Offset changed by Georg Fischer, Jun 26 2024

Status

approved