A064416 Number of integers q such that phiter(q)=n where phiter(n) = A064415(n).

1, 2, 5, 11, 26, 59, 137, 312, 719, 1651, 3816, 8757, 20202, 46440, 106957, 245989, 566561, 1303968, 3002247, 6910122, 15909143

Offset

0,2

Links

Table of n, a(n) for n=0..20.

Hartosh Singh Bal, Combinatorics of a Class of Completely Additive Arithmetic Functions<§a>, arXiv:2308.00455 [math.CO], 2023. See Table 12 p. 17.

Formula

If 2<=n<=6, a(n)=a(n-1)+3*a(n-2).

Crossrefs

Cf. A000010, A064415.

Sequence in context: A362740 A291233 A026787 * A006138 A291930 A238437

Adjacent sequences: A064413 A064414 A064415 * A064417 A064418 A064419

Keyword

nonn,more

Author

Christian WEINSBERG (cweinsbe(AT)fr.packardbell.org), Sep 30 2001

Extensions

a(14)-a(20) from Sean A. Irvine, Jul 07 2023

Status

approved