OFFSET
1,4
COMMENTS
Original name: If p is the product of k1-th prime, k2-th prime,..,kr-th prime then set a(n)=n-k1*k2*..*kr, if p is the k-th prime then set=n-k, a(1)=1 by convention. - Michael De Vlieger, Oct 23 2023
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = n - A003963(n) for n>1.
MATHEMATICA
Array[# - Times @@ PrimePi@ Flatten[ConstantArray[#1, #2] & @@@ FactorInteger[#]] &, 74] (* Michael De Vlieger, Oct 23 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jun 03 2010
EXTENSIONS
a(34) corrected by Georg Fischer, Dec 11 2022
Name edited by Michael De Vlieger, Oct 23 2023
STATUS
approved