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A302921
Values of A000010(m) where gcd(A000010(m), m) equals the number of solutions of A000010(m) = A000010(x), and m is the least solution.
1
20, 204, 444, 564, 744, 1160, 1284, 1416, 1644, 1704, 1812, 2124, 2172, 2480, 2604, 2844, 2892, 2964, 3084, 3156, 3192, 3320, 3324, 3396, 3492, 3560, 3576, 3756, 3972, 4164, 4404, 4476, 4520, 4572, 4740, 4764, 5004, 5352, 5360, 5364, 5496, 5532, 5604, 5772, 5840, 6320
OFFSET
1,1
FORMULA
gcd(A000010(m), m) = #{A000010(m) = A000010(x)}.
EXAMPLE
20 is a term because 25 is the least solution of 20 = A000010(x) and gcd(20,25) equals the number of solutions 5.
7812 is a term because 9121 is the least solution of 7812 = A000010(x) and gcd(7813,9121) equals the number of solutions 7.
1764 is not a term because 2107 is the least solution of 1764 = A000010(x) and gcd(1764,2107) = 49 does not equal the number of solutions 7.
PROG
(PARI) is(k) = gcd(k, invphiMin(k)) == invphiNum(k); \\ Amiram Eldar, Nov 16 2024, using Max Alekseyev's invphi.gp
CROSSREFS
Subsequence of A302838.
Sequence in context: A041766 A121088 A302838 * A334692 A325474 A364651
KEYWORD
nonn
AUTHOR
Torlach Rush, Apr 15 2018
EXTENSIONS
More terms from Amiram Eldar, Nov 16 2024
STATUS
approved