%I #21 Oct 01 2016 21:18:32
%S 1,1,7,73,793,8647,94321,1028881,11223367,122428153,1335486313,
%T 14567921287,158911647841,1733460204961,18909150606727,
%U 206267196469033,2250030010552633,24544062919609927,267734662105156561
%N a(n+1) = 11*a(n) - a(n-1) - 3, a(0)=a(1)=1.
%C The old entry with this sequence number was a duplicate of A039963.
%C The simultaneous equations (p+1)(p+2) == -1 (mod q), (q+1)(q+2) == -1 (mod p), where p and q are odd, have solutions {3, 3}, {3, 21}, {7, 73}, {21, 507}, {73, 793}, {793, 8647} and suggested this recurrence.
%H Vincenzo Librandi, <a href="/A092444/b092444.txt">Table of n, a(n) for n = 0..980</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (12,-12,1).
%H <a href="/index/Fi#FIXEDPOINTS">Index entries for sequences that are fixed points of mappings</a>
%F a(n) = 2*(A004190(n)-10*A004190(n-1))/3+1/3. G.f.: (1-11x+7x^2)/((1-x)(1-11x+x^2)). [From _R. J. Mathar_, Sep 20 2008]
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Sep 19 2008, based on emails from _M. F. Hasler_ and _Jim Nastos_ on Apr 25 2008
%E More terms from _R. J. Mathar_, Sep 20 2008