A334775 Number of permutations of 2 indistinguishable copies of 1..n with exactly n local maxima.

1, 3, 24, 339, 7392, 230217, 9689934, 529634931, 36463272996, 3086776079745, 315108659732034, 38170141911313467, 5412679282489599840, 888197438344278978537, 166988574370806672234630, 35659091146526471860555587, 8583030980293328579564829948, 2312892203852608268226402385617

Offset: 1

Author

Andrew Howroyd, May 11 2020

Keywords

• nonn

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..100

Crossrefs

Main diagonal of A334774.

Programs

PARI

\\ PeaksBySig defined in A334774.
a(n)={ PeaksBySig(vector(n,i,2), [n-1])[1] }