25172538050domain: NAppears in sequencesa(n) = 2*Fibonacci(2*n+2).at n=24A025169Number of permutations avoiding the patterns {1432,2431,3412,3421,4132,4231,4312,4321}; number of strong sorting class based on 1432.at n=25A111282First differences of A137976 after having added two leading ones.at n=20A138298