1,3

Table of n, a(n) for n=1..89.

For n>7 a(3n)=a(n)+2; a(3n+1)=a(n)+3; (3n+2)=a(n)+4

(PARI) a(n)=if(n<2, 1, n-2*valuation(n!*sum(i=1, n, 1/i), 3))

Cf. A056792.

Sequence in context: A144786 A247369 A009389 * A305972 A121845 A239639

Adjacent sequences: A091825 A091826 A091827 * A091829 A091830 A091831

nonn

Benoit Cloitre, Mar 09 2004

approved