A086328 - OEIS

%I #17 Feb 13 2018 12:58:17

%S 1,2,2,8,2,28,2,96,62,284,2,1504,2,3560,2738,16896,2,67636,2,235736,

%T 109334,707480,2,4376848,206282,10408792,5417630,48753784,2,212560504,

%U 2,739236864,278770214,2333737292,133401818,13837799440,2

%N Number of n X n circulant singular (0,1) matrices over the reals.

%C a(2*n+1) = A144926(2*n+1), n>0. a(2*p) = 2^p + binomial(2*p,p) if p is an odd prime, cf. A144926. - _Vladeta Jovovic_, Oct 02 2008

%H W. F. Lunnon, <a href="/A086328/b086328.txt">Table of n, a(n) for n = 1..39</a>

%H W. F. Lunnon, <a href="/A144926/a144926.txt">C program for A144926 and A086328</a>

%F a(n) = 2^n - A086323(n).

%F For a prime p, a(p) = 2 and the two circulants are those with all rows equal (0, 0, 0, ..., 0) or all rows equal (1, 1, 1, ..., 1).

%Y Cf. A086323, A086324.

%K nonn

%O 1,2

%A Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 30 2003

%E More terms from _Fred Lunnon_, Oct 28 2008

%E a(0) removed, a(1) corrected by _Max Alekseyev_, Sep 25 2009