A222464 a(n) = (n+6)/gcd(n*6,n+6), n >= 6.

1, 13, 7, 5, 4, 17, 1, 19, 5, 7, 11, 23, 2, 25, 13, 3, 7, 29, 5, 31, 8, 11, 17, 35, 1, 37, 19, 13, 10, 41, 7, 43, 11, 5, 23, 47, 4, 49, 25, 17, 13, 53, 3, 55, 14, 19, 29, 59, 5, 61, 31, 7, 16, 65, 11, 67, 17, 23, 35, 71, 2, 73, 37, 25, 19, 77, 13, 79, 20, 9, 41

Offset: 6

Author

Wolfdieter Lang, Feb 21 2013

Keywords

• nonn
• easy

Comments

This is the sixth column (m=6) of the triangle A221919.

Examples

			a(10) = numerator(16/60) = numerator(4/15) = 4 = 16/gcd(60,16) = 16/gcd(36,16).
		

Crossrefs

Cf. A221919, A000027(n+1) (m=1), A060819(n+2) (m=2), A106610(n+3) (m=3), A106617(n+4) (m=4), A132739(n+5) (m=5).

Formula

a(n) = A221919(n,6) = denominator(n*6/(n+6)) = numerator(n+6/n*6) = (n+6)/gcd(n*6,n+6) = (n+6)/gcd(36,n+6), n >= 6.