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A330747 Number of values of k, 1 <= k <= n, with A049559(k) = A049559(n), where A049559(n) = gcd(n - 1, phi(n)). 4
1, 2, 1, 3, 1, 4, 1, 5, 2, 6, 1, 7, 1, 8, 3, 9, 1, 10, 1, 11, 2, 12, 1, 13, 3, 14, 4, 1, 1, 15, 1, 16, 4, 17, 5, 18, 1, 19, 6, 20, 1, 21, 1, 22, 5, 23, 1, 24, 2, 25, 7, 2, 1, 26, 8, 27, 6, 28, 1, 29, 1, 30, 9, 31, 2, 1, 1, 32, 7, 3, 1, 33, 1, 34, 10, 4, 8, 35, 1, 36, 11, 37, 1, 38, 9, 39, 12, 40, 1, 41, 2, 42, 10, 43, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Ordinal transform of A049559.

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; };

A049559(n) = gcd(n-1, eulerphi(n));

v330747 = ordinal_transform(vector(up_to, n, A049559(n)));

A330747(n) = v330747[n];

CROSSREFS

Cf. A000010, A049559, A209211.

Cf. also A081373, A303756, A330756.

Sequence in context: A194746 A198336 A330756 * A337785 A290980 A007381

Adjacent sequences:  A330744 A330745 A330746 * A330748 A330749 A330750

KEYWORD

nonn

AUTHOR

Antti Karttunen, Dec 30 2019

STATUS

approved

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Last modified June 16 13:05 EDT 2021. Contains 345057 sequences. (Running on oeis4.)