Search: id:A121285 Results 1-1 of 1 results found. %I A121285 %S A121285 1,1,2,4,10,22,54,120,284,626,1438,3136,7044,15212,33596,71952,156856, 333610, %T A121285 719886,1522224,3257972,6855476,14574772,30541264,64571400,134827252,283727564, %U A121285 590608960,1237926184,2569953496,5368225848,11118205088,23155034480,47856472218 %N A121285 a(0) = 1; for n>0, a(n) = (n+3)*2^(n-2)-n*binomial(n-1, floor( (n-1)/ 2 ))-(n-1)*binomial(n-2,floor((n-2)/2)). %D A121285 A. Bernini, F. Disanto, R. Pinzani and S. Rinaldi, Permutations defining convex permutominoes, preprint, 2007. [See S_{n+1}.] %Y A121285 Sequence in context: A075560 A078040 A164990 this_sequence A030234 A148086 A076875 %Y A121285 Adjacent sequences: A121282 A121283 A121284 this_sequence A121286 A121287 A121288 %K A121285 nonn %O A121285 0,3 %A A121285 N. J. A. Sloane (njas(AT)research.att.com), Jul 28 2007 Search completed in 0.001 seconds