Search: id:A023427 Results 1-1 of 1 results found. %I A023427 %S A023427 1,1,1,1,1,2,4,7,11,17,28,49,87,152,262,453,794,1408, %T A023427 2507,4462,7943,14179,25415,45713,82398,148731,268859, %U A023427 486890,883411,1605582,2922259,5325377,9716564 %N A023427 Generalized Catalan Numbers. %t A023427 Clear[ a ]; a[ 0 ]=1; a[ n_Integer ] := a[ n ]=a[ n-1 ]+Sum[ a[ k ]*a[ n-4-k ], {k, 1, n-4} ]; %Y A023427 Cf. A000108, A001006, A004148, A006318. %Y A023427 Sequence in context: A023428 A093911 A152398 this_sequence A129929 A073738 A137631 %Y A023427 Adjacent sequences: A023424 A023425 A023426 this_sequence A023428 A023429 A023430 %K A023427 nonn,easy %O A023427 0,6 %A A023427 Olivier Gerard (olivier.gerard(AT)gmail.com) Search completed in 0.001 seconds