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A362485
Number of numbers k such that iphi(k) = n, where iphi is the infinitary totient function A091732.
7
2, 2, 2, 2, 0, 4, 0, 4, 0, 2, 0, 6, 0, 0, 2, 4, 0, 4, 0, 2, 0, 2, 0, 10, 0, 0, 0, 2, 0, 6, 0, 4, 0, 0, 0, 8, 0, 0, 0, 4, 0, 2, 0, 2, 2, 2, 0, 14, 0, 0, 0, 2, 0, 2, 0, 2, 0, 2, 0, 10, 0, 0, 0, 4, 0, 4, 0, 0, 0, 2, 0, 14, 0, 0, 0, 0, 0, 2, 0, 8, 0, 2, 0, 4, 0, 0
OFFSET
1,1
COMMENTS
a(n) is even for all n, because if k is a solution to iphi(k) = n, and A007814(k) is even, then 2*k is also a solution, i.e., iphi(2*k) = n.
LINKS
FORMULA
a(A362486(n)) = 0.
MATHEMATICA
a[n_] := Length[invIPhi[n]]; Array[a, 100] (* using the function invIPhi from A362484 *)
CROSSREFS
Row lengths of A362484.
Cf. A007814, A091732, A362486 (positions of 0's), A362487 (indices of records).
Similar sequences: A014197, A063740, A361967, A362181.
Sequence in context: A333180 A127444 A241477 * A268243 A159782 A268242
KEYWORD
nonn
AUTHOR
Amiram Eldar, Apr 22 2023
STATUS
approved