OFFSET
1,1
COMMENTS
First differs from A287483 in having 222.
First differs from A350352 in having 420.
A number's prime signature (row n of A124010) is the sequence of positive exponents in its prime factorization, so a number has distinct prime multiplicities iff all the exponents in its prime signature are distinct.
EXAMPLE
Selected terms together with their prime indices:
660: {1,1,2,3,5}
798: {1,2,4,8}
840: {1,1,1,2,3,4}
3120: {1,1,1,1,2,3,6}
9900: {1,1,2,2,3,3,5}
MATHEMATICA
strsig[n_]:=UnsameQ@@Last/@FactorInteger[n]
Select[Range[100], Function[n, Select[Divisors[n], strsig[#]&&strsig[n/#]&]=={}]]
CROSSREFS
A336500 has zeros at these positions.
A007425 counts divisors of divisors.
A056924 counts divisors greater than their quotient.
A074206 counts strict chains of divisors from n to 1.
A130091 lists numbers with distinct prime multiplicities.
A181796 counts divisors with distinct prime multiplicities.
A327498 is the maximum divisor with distinct prime multiplicities.
KEYWORD
nonn
AUTHOR
Gus Wiseman, Aug 06 2020
STATUS
approved