A222464 - OEIS

%I #7 Nov 17 2022 18:10:03

%S 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,

%T 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,

%U 16,65,11,67,17,23,35,71,2,73,37,25,19,77,13,79,20,9,41

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

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

%F 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.

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

%Y 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).

%K nonn,easy

%O 6,2

%A _Wolfdieter Lang_, Feb 21 2013