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A325230
Numbers of the form p^k * q, p and q prime, p > q, k > 0.
4
6, 10, 14, 15, 18, 21, 22, 26, 33, 34, 35, 38, 39, 46, 50, 51, 54, 55, 57, 58, 62, 65, 69, 74, 75, 77, 82, 85, 86, 87, 91, 93, 94, 95, 98, 106, 111, 115, 118, 119, 122, 123, 129, 133, 134, 141, 142, 143, 145, 146, 147, 155, 158, 159, 161, 162, 166, 177, 178
OFFSET
1,1
LINKS
EXAMPLE
The sequence of terms together with their prime indices begins:
6: {1,2}
10: {1,3}
14: {1,4}
15: {2,3}
18: {1,2,2}
21: {2,4}
22: {1,5}
26: {1,6}
33: {2,5}
34: {1,7}
35: {3,4}
38: {1,8}
39: {2,6}
46: {1,9}
50: {1,3,3}
51: {2,7}
54: {1,2,2,2}
55: {3,5}
57: {2,8}
58: {1,10}
MAPLE
filter:= proc(n) local F;
F:= sort(ifactors(n)[2], (a, b)-> a[1]<b[1]);
nops(F) = 2 and F[1, 2] = 1;
end proc:
select(filter, [$6..200]); # Robert Israel, Apr 14 2019
MATHEMATICA
Select[Range[100], PrimeOmega[#/Power@@FactorInteger[#][[-1]]]==1&]
PROG
(Python)
from sympy import factorint
A325230_list = [n for n, m in ((n, factorint(n)) for n in range(2, 10**6)) if len(m) == 2 and m[min(m)] == 1] # Chai Wah Wu, Apr 16 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Apr 13 2019
STATUS
approved