A152517 1/56 of the number of permutations of 7 indistinguishable copies of 1..n with exactly 2 local maxima.
0, 3, 412, 50080, 6016512, 722051072, 86646800384, 10397622337536, 1247714738176000, 149725769101213696, 17967092296776155136, 2156051075653940805632, 258726129078829378961408, 31047135489462617851822080, 3725656258735540805375623168, 447078751048265125343493357568
Offset: 1
Keywords
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..200
Programs
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PARI
a(n) = {(13*120^(n-1) - 13*8^(n-1) - 14*(n-1)*8^(n-1))/448} \\ Andrew Howroyd, May 10 2020
Formula
a(n) = (13*120^(n-1) - 13*8^(n-1) - 14*(n-1)*8^(n-1))/448. - Andrew Howroyd, May 10 2020
Extensions
Terms a(7) and beyond from Andrew Howroyd, May 10 2020