a(n) = number of permutations of {1,...,n} which are twice but not 3-times reformable.
A055459
a(n) = number of permutations of {1,...,n} which are twice but not 3-times reformable.
Terms
- a(0) =2a(1) =1a(2) =11a(3) =14a(4) =81a(5) =242a(6) =1142a(7) =4771a(8) =29009a(9) =127876a(10) =805947a(11) =4868681a(12) =31862753
External references
- oeis: A055459