A022002 Decimal expansion of 1/998.

0, 0, 1, 0, 0, 2, 0, 0, 4, 0, 0, 8, 0, 1, 6, 0, 3, 2, 0, 6, 4, 1, 2, 8, 2, 5, 6, 5, 1, 3, 0, 2, 6, 0, 5, 2, 1, 0, 4, 2, 0, 8, 4, 1, 6, 8, 3, 3, 6, 6, 7, 3, 3, 4, 6, 6, 9, 3, 3, 8, 6, 7, 7, 3, 5, 4, 7, 0, 9, 4, 1, 8, 8, 3, 7, 6, 7, 5, 3, 5, 0, 7, 0, 1, 4, 0, 2, 8, 0, 5, 6, 1, 1, 2, 2, 2, 4, 4, 4

Offset

0,6

Comments

Generalization:

1/8 = sum (2^i/10^(i+1)), i >= 0,

1/98 = sum (2^i/100^(i+1)), i >= 0,

1/998 = sum (2^i/1000^(i+1)), i >= 0, (this sequence)

1/9998 = sum (2^i/10000^(i+1)), i >= 0, ... - Daniel Forgues, Oct 28 2011

Links

Table of n, a(n) for n=0..98.

Mario Raso, Integer Sequences in Cryptography: A New Generalized Family and its Application, Ph. D. Thesis, Sapienza University of Rome (Italy 2025). See p. 9.

Mario Raso and Daniele Venturi, On integer sequences in cryptography, J. Math. Cryptol. 20(1) (2026), Article 20240033.

Example

0.0010020040080160320641282565130260521042084168336673...

Mathematica

First[RealDigits[1/998, 10, 100, -1]] (* Paolo Xausa, Sep 24 2025 *)

Crossrefs

Cf. A020821 (1/8), A021102 (1/98), A236799 (1/9998).

Sequence in context: A077958 A077959 A392074 * A392042 A084658 A326404

Adjacent sequences: A021999 A022000 A022001 * A022003 A022004 A022005

Keyword

nonn,cons,easy

Author

N. J. A. Sloane

Status

approved