A321692 Digits of the 2-adic integer exp(-4).

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

Offset: 0

Author

Jianing Song, Nov 17 2018

Keywords

• nonn
• base

Comments

This is the multiplicative inverse of A320815.

Examples

			exp(-4) = ...00110000100100101000011101101111110000101.
		

Links

• Wikipedia, p-adic number

Crossrefs

Cf. A320815, A321689.

Programs

PARI

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

PARI

a(n) = lift(exp(-4 + O(2^(n+1))))\2^n;

Formula

a(n) = (A321689(n+1) - A321689(n))/2^n.