I make matrices from the sequence of Catalan numbers 1,2,5,14,42,132,429,1430,4862,... Such matrices satisfy all criterion: 1)All numbers are positive integers 2) Determinants of all matrices are equal to 1 But I get WA2 I got AC using your method with first submission. Edited by author 10.08.2009 18:08 Use big numbers... I use your method, but I got wa6. :( please help me. Edited by author 11.11.2009 21:43 Wow, its great, but how did you get to Catalan's numbers? please said me, what answer when n=20? thanks burn in hell with you spoiler Edited by author 03.08.2013 03:37  0 1 1   1 1 1  = 1  1 1 0  Is it correct hankel matrix and answer for n = 3? It is a Hankel matrix, but is not answer, because 0 == 0 != 1 and  0 1   1 1  == 1 != 1 Thank you for answer! I did not notice some conditions... Edited by author 17.08.2008 16:05 Apparently we are not allowed to use negative numbers. In the problem description we know that all output should be positive integers.But I submit a solution which contains '0' but it got accepted.I think the Check Program has something wrong. Statement isn't fully updated: Output positive integers α1, α2, …, α2n−1 ... But they must be only nonnegative! 
