A295310 a(n) = gcd(n, A062401(n)), where A062401(n) = phi(sigma(n)).

1, 2, 1, 2, 1, 2, 1, 8, 3, 2, 1, 12, 1, 2, 1, 2, 1, 6, 1, 4, 1, 2, 1, 8, 5, 2, 1, 4, 1, 6, 1, 4, 1, 2, 1, 36, 1, 2, 3, 8, 1, 2, 1, 4, 3, 2, 1, 12, 1, 10, 3, 2, 1, 2, 1, 8, 1, 2, 1, 12, 1, 2, 3, 2, 1, 6, 1, 4, 1, 2, 1, 24, 1, 2, 15, 4, 1, 6, 1, 20, 1, 2, 1, 12, 1, 2, 1, 8, 1, 18, 1, 4, 1, 2, 1, 24, 1, 2, 3, 20, 1, 6, 1, 8, 1

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Formula

a(n) = gcd(n, A000010(A000203(n))).

Mathematica

Array[GCD[#, EulerPhi[DivisorSigma[1, #]]] &, 105] (* Michael De Vlieger, Nov 23 2017 *)

Prog

(PARI) a(n) = gcd(n, eulerphi(sigma(n))); \\ Michel Marcus, Nov 23 2017

Crossrefs

Cf. A000010, A000203, A062401, A295301, A295311, A295312, A295313.

Sequence in context: A215136 A318658 A318512 * A359509 A335665 A369239

Adjacent sequences: A295307 A295308 A295309 * A295311 A295312 A295313

Keyword

nonn

Author

Antti Karttunen, Nov 22 2017

Status

approved