Search: id:A056990 Results 1-1 of 1 results found. %I A056990 %S A056990 2,8,192,22272,11550720,25629327360,236229525504000,8858686914082897920, %T A056990 1331751782100764385607680 %N A056990 Number of nonsingular n X n (-1,1)-matrices. %H A056990 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %Y A056990 Cf. A055165, A056989. %Y A056990 A056990(n) = 2^(2*n-1) * A055165(n-1). %Y A056990 Sequence in context: A156526 A009505 A028368 this_sequence A070235 A057194 A012539 %Y A056990 Adjacent sequences: A056987 A056988 A056989 this_sequence A056991 A056992 A056993 %K A056990 nonn,nice %O A056990 1,1 %A A056990 Eric Weisstein (eric(AT)weisstein.com) %E A056990 a(5) from Winston C. Yang (winston(AT)cs.wisc.edu), Aug 26 2000. Further terms computed from A055165 by David desJardins (david(AT)desjardins.org), Apr 22 2001 %E A056990 a(9) from Max Alekseyev, computed from A055165, Jan 15 2007 Search completed in 0.001 seconds