OFFSET
1,2
COMMENTS
a(11) = 2^(2^10) has 309 digits and is too large to be included in the data section.
See the link for more values of this sequence.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..12
Amiram Eldar, Table of n, a(n) for n = 1..100 (given by prime factorizations)
EXAMPLE
a(2) = 4 since 4 is the least number with 2 exponential divisors, 2 and 4.
MATHEMATICA
f[p_, e_] := DivisorSigma[0, e]; d[1] = 1; d[n_] := Times @@ (f @@@ FactorInteger[n]); max = 6; s = Table[0, {max}]; c = 0; n = 1; While[c < max, i = d[n]; If[i <= max && s[[i]] == 0, c++; s[[i]] = n]; n++]; s (* ineffective for n > 6 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jan 01 2021
STATUS
approved