OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
The sequence of terms together with their prime indices begins:
2: {1}
4: {1,1}
8: {1,1,1}
10: {1,3}
14: {1,4}
15: {2,3}
16: {1,1,1,1}
20: {1,1,3}
22: {1,5}
26: {1,6}
32: {1,1,1,1,1}
34: {1,7}
38: {1,8}
40: {1,1,1,3}
44: {1,1,5}
45: {2,2,3}
46: {1,9}
50: {1,3,3}
52: {1,1,6}
55: {3,5}
MATHEMATICA
Select[Range[100], Count[If[#==1, {}, FactorInteger[#]], {p_, _}/; Divisible[#, PrimePi[p]]]==1&]
PROG
(PARI) isok(n) = my(f=factor(n)[, 1]); sum(k=1, #f, (n % primepi(f[k])) == 0) == 1; \\ Michel Marcus, Mar 22 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 21 2019
STATUS
approved