A334216 a(n) is the number of distinct terms in the n-th row of A334215.

1, 2, 2, 3, 2, 2, 2, 3, 3, 2, 2, 3, 2, 2, 2, 4, 2, 3, 2, 3, 2, 2, 2, 3, 3, 2, 3, 3, 2, 2, 2, 4, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 3, 3, 2, 2, 4, 3, 3, 2, 3, 2, 3, 2, 3, 2, 2, 2, 3, 2, 2, 3, 5, 2, 2, 2, 3, 2, 2, 2, 4, 2, 2, 3, 3, 2, 2, 2, 4, 4, 2, 2, 3, 2, 2, 2

Offset: 1

Author

Rémy Sigrist, Apr 19 2020

Keywords

• nonn

Crossrefs

Cf. A000005, A000267, A334215, A334217.

Programs

PARI

a(n) = { my (f=factor(n)); #Set(apply (k -> prod (i=1, #f~, f[i,1]^(f[i,2]\k)), [1..1+if (n==1, 0, vecmax(f[,2]~))])) }

Formula

a(n) <= A000005(n).

a(p^k) = A000267(k) for any k >= 0 and prime number p.