129514

Appears in sequences

• Number of reduced words of length n in the Weyl group E_7 on 7 generators and order 2903040.at n=30A162493
• Number of reduced words of length n in the Weyl group E_7 on 7 generators and order 2903040.at n=33A162493
• Let v = list of denominators of Farey series of order n (see A006843); a(n) = sum of products of adjacent terms of v.at n=30A278046
• a(n) is the number of 2 X 2 matrices with elements 1..n where at least one row and at least one column is strictly increasing.at n=22A390922