OFFSET
1,4
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..20000
FORMULA
MAPLE
a:= n-> add((-1)^i*padic[ordp](n, i), i=2..n):
seq(a(n), n=1..78); # Alois P. Heinz, Jan 15 2024
MATHEMATICA
z = 70; Sum[(-1)^k IntegerExponent[Range[z], k], {k, 2, z}]
PROG
(PARI) a(n) = sum(k=2, n, (-1)^k * valuation(n, k)); \\ Michel Marcus, Jan 18 2024
CROSSREFS
KEYWORD
sign
AUTHOR
Friedjof Tellkamp, Jan 15 2024
STATUS
approved