A215252 Number of indecomposable permutations sortable using two parallel stacks.

0, 1, 1, 3, 12, 56, 289, 1602, 9367, 57075, 359346, 2323416, 15356446, 103389175, 707107627, 4901988047, 34384943850, 243694702311, 1742953208739, 12567593026554, 91280392585747, 667341975412356, 4907899368783645, 36289929612761691, 269660272111724536, 2012845416966620068, 15087243969226496324, 113521159338891300347, 857211201390859034536

Offset: 0

Author

N. J. A. Sloane, Sep 07 2012. a(0)=0 added by N. J. A. Sloane, Sep 12 2012

Keywords

• nonn

Comments

Suggested by Peter Doyle in an email message, Sep 04 2012

Links

• N. J. A. Sloane, Table of n, a(n) for n = 0..100

Crossrefs

Cf. A003319, A216040, A182216, A215257.

Formula

INVERTi transform of A216040.