A177284
Number of permutations of 2 copies of 1..n with all adjacent differences <= 3 in absolute value.
Original entry on oeis.org
1, 1, 6, 90, 2520, 41580, 516180, 6068622, 76331906, 958679970, 11679900408, 138047313960, 1610654864328, 18649754961744, 214256589488616, 2439692058769566, 27562317214408488, 309367132582535226, 3453299423388485028, 38354816922190327314, 424048220090513056908
Offset: 0
A177285
Number of permutations of 2 copies of 1..n with all adjacent differences <= 4 in absolute value.
Original entry on oeis.org
1, 1, 6, 90, 2520, 113400, 3356640, 75336660, 1500131820, 29660400822, 620330067782, 13125403608162, 274194614811528, 5605288189594200, 112437639146871360, 2235073249396108440, 44209749453949113840, 870798759948756386976, 17069437222534487122608, 332789644153015982087550, 6455422726721469064982952
Offset: 0
a(0)=1 prepended and terms a(13) and beyond from
Andrew Howroyd, May 14 2020
A177286
Number of permutations of 2 copies of 1..n with all adjacent differences <= 5 in absolute value.
Original entry on oeis.org
1, 1, 6, 90, 2520, 113400, 7484400, 349272000, 12629539440, 394462558980, 11673071453460, 348672825749478, 10924880404749722, 348078897908489130, 11059657083803795688, 346844915294462956440, 10705742604901078977600
Offset: 0
Showing 1-3 of 3 results.
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