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A062951
a(n) = H(A005117(n)) where H(n) is the half-totient function and A005117(n) are the squarefree numbers.
1
1, 2, 1, 3, 2, 5, 6, 3, 4, 8, 9, 6, 5, 11, 6, 14, 4, 15, 10, 8, 12, 18, 9, 12, 20, 6, 21, 11, 23, 16, 26, 20, 18, 14, 29, 30, 15, 24, 10, 33, 22, 12, 35, 36, 18, 30, 12, 39, 20, 41, 32, 21, 28, 44, 36, 30, 23, 36, 48, 50, 16, 51, 24, 26, 53, 54, 20, 36, 56, 18, 44, 29, 48, 30, 40
OFFSET
3,2
LINKS
FORMULA
a(n) = A023022(A005117(n)). - Amiram Eldar, Mar 10 2024
MATHEMATICA
EulerPhi[Select[Range[3, 150], SquareFreeQ]]/2 (* Amiram Eldar, Mar 10 2024 *)
PROG
(PARI) H(n) = eulerphi(n)/2;
j=[]; for(n = 3, 200, if(issquarefree(n), j = concat(j, H(n)))); j
CROSSREFS
Sequence in context: A325193 A079974 A102517 * A263150 A145794 A176741
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 21 2001
STATUS
approved