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 A261479 Number of set partitions of [2n] into exactly n parts such that no part contains two elements with a circular distance less than three. 2
 1, 0, 0, 1, 7, 458, 18944, 858023, 42615547, 2331292564, 140077132527, 9199520194445, 656844469384222, 50720708063406821, 4215138323234299756, 375319710150454887887, 35660986210126871452435, 3602425696957042245685448, 385625195068544676072425069 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS The circular distance of 1 and n is 1 (for n>1). LINKS Alois P. Heinz, Table of n, a(n) for n = 0..50 FORMULA a(n) = A261477(2n,n). EXAMPLE a(0) = 1: {}. a(3) = 1: 14|25|36. a(4) = 7: 14|26|37|58, 14|27|36|58, 15|26|37|48, 15|26|38|47, 15|27|36|48, 16|25|37|48, 16|25|38|47. a(5) = 458: 147|258|3,10|6|9, 147|258|36|9|10, 147|258|39|6|10, ..., 1|29|36,10|47|58, 1|29|36|47,10|58, 1|2|369|47,10|58. CROSSREFS Cf. A261477. Sequence in context: A009660 A024097 A203060 * A241363 A196540 A215890 Adjacent sequences: A261476 A261477 A261478 * A261480 A261481 A261482 KEYWORD nonn AUTHOR Alois P. Heinz, Aug 20 2015 STATUS approved

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Last modified February 29 19:20 EST 2024. Contains 370428 sequences. (Running on oeis4.)