A309768 Digits of the 2-adic integer arctanh(4).

0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1

Offset

0

Comments

arctanh(x) = x + x^3/3 + x^5/5 + x^7/7 + ...

Links

Table of n, a(n) for n=0..87.

Wikipedia, p-adic number

Formula

a(n) = (A309767(n+1) - A309767(n))/2^n.

Example

arctanh(4) = ...0100000010101110111011111001111011000100.

Prog

(PARI) a(n) = lift(sum(i=0, (n-2)/4, Mod(4^(2*i+1)/(2*i+1), 2^(n+1))))\2^n

Crossrefs

Cf. A309754, A309766, A309767.

Sequence in context: A358227 A284524 A226474 * A080887 A099395 A182581

Adjacent sequences: A309765 A309766 A309767 * A309769 A309770 A309771

Keyword

nonn,base

Author

Jianing Song, Aug 16 2019

Status

approved