A317923 Integers m such that A071324(m) = A206369(m).

1, 2, 3, 4, 5, 7, 8, 9, 11, 13, 16, 17, 19, 20, 23, 25, 27, 28, 29, 31, 32, 37, 41, 43, 44, 47, 49, 52, 53, 59, 61, 64, 67, 68, 71, 73, 76, 79, 81, 83, 89, 92, 97, 99, 100, 101, 103, 107, 109, 113, 116, 117, 121, 124, 125, 127, 128, 131, 137, 139, 148, 149, 151, 153, 157

Offset

1,2

Comments

Powers of primes (A000961) are in this sequence.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Prog

(PARI) a071324(n) = my(d=Vecrev(divisors(n))); sum(k=1, #d, (-1)^(k+1)*d[k]);
a206369(n) = a(n) = sumdiv(n, d, eulerphi(n/d) * issquare(d));
isok(n) = a071324(n) == a206369(n);

Crossrefs

Cf. A000961, A071324, A206369, A317924 (a subsequence).

Sequence in context: A133811 A316525 A119314 * A371058 A344979 A273130

Adjacent sequences: A317920 A317921 A317922 * A317924 A317925 A317926

Keyword

nonn

Author

Michel Marcus, Aug 11 2018

Status

approved