OFFSET
0,3
COMMENTS
This sequence maps natural numbers uniquely onto integers.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..2309 (terms for n < 2*3*5*7*11)
EXAMPLE
For n = 42:
- 42 = 1 * 5*3*2 + 2 * 3*2 + 0 * 2 + 0 * 1.
- so a(42) = 1 * -5*3*2 + 2 * 3*2 + 0 * -2 + 0 * 1 = -18.
PROG
(PARI) a(n) = { my (f=1, v=0); forprime (p=2, oo, if (n, v += f*(n%p); n\=p; f*=-p, return (v))) }
CROSSREFS
KEYWORD
sign,base
AUTHOR
Rémy Sigrist, Mar 05 2022
STATUS
approved
