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a(n) = n * A002445(n).
1

%I #12 Jul 03 2015 14:43:31

%S 0,6,60,126,120,330,16380,42,4080,7182,3300,1518,32760,78,12180,

%T 214830,8160,102,34545420,114,270600,37926,15180,6486,1113840,1650,

%U 41340,21546,24360,10266,1703601900,186,16320,2135826,1020,164010,5043631320,222,1140

%N a(n) = n * A002445(n).

%C a(n+1) is a multiple of A040031(n+1), sequence of period 2: 6, 12.

%C a(n) is divisible by A040879(n)=30 followed by the sequence of period 2: 6, 60. See A040214 and A165734.

%C Note that A164877(n) + A000367(n) = A164558(2n).

%H Colin Barker, <a href="/A228838/b228838.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = A176328(2n) - A000367(n).

%F a(n) = A164877(n)/2.

%F a(n+1) = A111008(n) * A036283(n+1).

%F 2*a(n) = A164558(2n) - A000367(n).

%F a(n) = A164558(2n) - A176328(2n).

%e a(0)=0*1, a(1)=1*6, a(2)=2*30=60,, a(3)=3*42=126.

%o (PARI) a(n)=n*denominator(bernfrac(2*n))

%K nonn

%O 0,2

%A _Paul Curtz_, Sep 05 2013

%E Typo in data fixed by _Colin Barker_, Jul 03 2015