OFFSET
1,2
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
The terms together with their prime indices begin:
1: {}
4: {1,1}
8: {1,1,1}
9: {2,2}
16: {1,1,1,1}
24: {1,1,1,2}
25: {3,3}
27: {2,2,2}
32: {1,1,1,1,1}
36: {1,1,2,2}
40: {1,1,1,3}
48: {1,1,1,1,2}
49: {4,4}
54: {1,2,2,2}
56: {1,1,1,4}
64: {1,1,1,1,1,1}
MAPLE
filter:= proc(n) local F, t;
F:= ifactors(n)[2];
add(t[2], t=F) >= 2*nops(F)
end proc:
select(filter, [$1..1000]); # Robert Israel, Mar 22 2023
MATHEMATICA
Select[Range[100], 2*PrimeNu[#]<=PrimeOmega[#]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 14 2023
STATUS
approved