530100

Appears in sequences

• Triangle read by rows: T(n,k) is the number of permutations p of [n] such that the length of the longest 2-stack sortable initial segment of p is equal to k.at n=51A094785
• Mutually-praising pairs excluding autobiographical numbers A046043. Version 1: both numbers in a pair have at most 10 digits.at n=20A138481
• Mutually-praising pairs excluding autobiographical numbers A138480. Version 2: numbers may have more than 10 digits.at n=25A138482
• a(n) = Sum_{k<n} ((2^n-1) mod (2^k-1)).at n=37A329162