A294896 a(n) = gcd(A000203(n), A005187(n)).

1, 3, 4, 7, 2, 2, 1, 15, 1, 18, 1, 2, 1, 1, 2, 31, 2, 1, 5, 2, 1, 1, 6, 2, 1, 7, 10, 1, 6, 8, 1, 63, 16, 6, 1, 7, 1, 1, 2, 6, 1, 3, 2, 1, 2, 8, 1, 2, 19, 1, 2, 1, 6, 8, 3, 1, 10, 2, 1, 4, 1, 1, 8, 127, 4, 2, 1, 2, 3, 1, 6, 1, 1, 1, 2, 1, 6, 8, 1, 2, 1, 7, 6, 1, 2, 12, 1, 1, 6, 2, 1, 12, 1, 3, 8, 2, 1, 1, 2, 1, 6, 8, 1, 5, 2

Offset

1,2

Links

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

Formula

a(n) = gcd(A000203(n), A005187(n)).

a(n) = gcd(A000203(n),abs(A294898(n))) = gcd(A005187(n),abs(A294898(n))), where A294898(n) = A005187(n) - A000203(n).

a(n) = A000203(n)/A295655(n) = A005187(n)/A295656(n).

Mathematica

Array[GCD[DivisorSigma[1, #], IntegerExponent[(2 #)!, 2]] &, 105] (* Michael De Vlieger, Nov 26 2017 *)

Prog

(Scheme) (define (A294896 n) (gcd (A000203 n) (A005187 n)))

Crossrefs

Cf. A000203, A005187, A294898, A294899, A295655, A295656.

Sequence in context: A072079 A116073 A166043 * A021292 A230159 A105828

Adjacent sequences: A294893 A294894 A294895 * A294897 A294898 A294899

Keyword

nonn

Author

Antti Karttunen, Nov 25 2017

Status

approved