A363249 Leading digit of 9^n.

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

Offset

0,2

References

He, Xinwei; Hildebrand, A J; Li, Yuchen; Zhang, Yunyi, Complexity of Leading Digit Sequences, Discrete Mathematics and Theoretical Computer Science; 22 (2020), #14.

Links

Seiichi Manyama, Table of n, a(n) for n = 0..10000

Formula

a(n) = A000030(A001019(n)).

a(n) = A060956(2*n).

Mathematica

a[n_] := IntegerDigits[9^n][[1]]; Array[a, 100, 0] (* Amiram Eldar, Jul 15 2023 *)

Prog

(PARI) a(n) = digits(9^n)[1];

Crossrefs

Cf. A008952, A060956, A111395, A362871, A363093, A364185.

Cf. A000030, A001019, A008570.

Sequence in context: A342115 A090671 A132673 * A107927 A019890 A066666

Adjacent sequences: A363246 A363247 A363248 * A363250 A363251 A363252

Keyword

nonn,base,easy

Author

Seiichi Manyama, Jul 15 2023

Status

approved