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Maximum number of distinct parts in a self-conjugate partition of n, or 0 if n=2.
2

%I #6 Jun 24 2014 01:08:21

%S 0,1,0,2,1,2,3,2,3,2,4,3,4,3,4,5,4,5,4,5,4,6,5,6,5,6,5,6,7,6,7,6,7,6,

%T 7,6,8,7,8,7,8,7,8,7,8,9,8,9,8,9,8,9,8,9,8,10,9,10,9,10,9,10,9,10,9,

%U 10,11,10,11,10,11,10,11,10,11,10,11,10,12,11,12,11,12,11,12,11,12,11

%N Maximum number of distinct parts in a self-conjugate partition of n, or 0 if n=2.

%C There are no self-conjugate partitions of 2, so we set a(2)=0.

%F a(n) = r - (s mod 2), where n = r(r+1)/2 + s with 0 <= s <= r; i.e. r = floor((sqrt(8n+1)-1)/2).

%t r[n_] := Floor[(Sqrt[8n+1]-1)/2]; s[n_] := n-r[n](r[n]+1)/2; a[n_] := r[n]-Mod[s[n], 2]

%Y Cf. A000700, A067694.

%K easy,nonn

%O 0,4

%A _Naohiro Nomoto_, Feb 05 2002

%E Edited by _Dean Hickerson_, Feb 15 2002