Number of derangements of {1,2,...,n} having no adjacent transpositions.

A177258

Number of derangements of {1,2,...,n} having no adjacent transpositions.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =2a(4) =7a(5) =36a(6) =225a(7) =1610a(8) =13104a(9) =119548a(10) =1208583a(11) =13413960a(12) =162176105a(13) =2121703324a(14) =29866022640a(15) =450112042926

External references