A330739 Number of values of k, 1 <= k <= n, with A047994(k) = A047994(n), where A047994 is unitary totient function uphi(n).

1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 3, 2, 1, 1, 3, 1, 2, 3, 2, 1, 1, 1, 4, 1, 2, 1, 4, 1, 1, 1, 2, 2, 3, 1, 3, 4, 2, 1, 5, 1, 2, 1, 2, 1, 3, 1, 5, 2, 2, 1, 2, 2, 2, 3, 3, 1, 6, 1, 4, 2, 1, 3, 2, 1, 4, 1, 7, 1, 1, 1, 4, 5, 1, 2, 8, 1, 3, 1, 3, 1, 5, 1, 3, 2, 2, 1, 3, 2, 2, 4, 2, 3, 1, 1, 6, 2, 4, 1, 4, 1, 1, 7

Offset

1,2

Comments

Ordinal transform of A047994.

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Prog

(PARI)
up_to = 65537;
ordinal_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), pt); for(i=1, length(invec), if(mapisdefined(om, invec[i]), pt = mapget(om, invec[i]), pt = 0); outvec[i] = (1+pt); mapput(om, invec[i], (1+pt))); outvec; };
A047994(n) = { my(f=factor(n)~); prod(i=1, #f, (f[1, i]^f[2, i])-1); };
v330739 = ordinal_transform(vector(up_to, n, A047994(n)));
A330739(n) = v330739[n];

Crossrefs

Cf. A047994.

Cf. also A081373 (ordinal transform of Euler totient function phi), A331177.

Sequence in context: A351408 A205788 A214054 * A076398 A086257 A161098

Adjacent sequences: A330736 A330737 A330738 * A330740 A330741 A330742

Keyword

nonn

Author

Antti Karttunen, Jan 11 2020

Status

approved