OFFSET
0,2
COMMENTS
EXAMPLE
Table begins:
1;
2;
3, 4;
4, 6, 8;
5, 8, 9, 12, 16;
6, 10, 12, 16, 18, 24, 32;
7, 12, 15, 16, 20, 24, 27, 32, 36, 48, 64;
8, 14, 18, 20, 24, 30, 32, 36, 40, 48, 54, 64, 72, 96, 128;
...
Numbers k with Omega(k) = 2 are either of the form p^2 with p prime, or of the form p1*p2 with p1 and p2 being distinct primes. The corresponding numbers of divisors are 3 and 4, respectively. Therefore the second row is {3, 4}.
MATHEMATICA
row[n_] := Union[Times @@ (# + 1) & /@ IntegerPartitions[n]]; Array[row, 9, 0] // Flatten
PROG
(PARI) row(n) = { my (m=Map()); forpart(p=n, mapput(m, prod(k=1, #p, 1+p[k]), 0)); Vec(m) } \\ Rémy Sigrist, Jun 17 2022
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Amiram Eldar, Jun 16 2022
STATUS
approved