9615053952domain: NAppears in sequencesa(n) = 2*Fibonacci(2*n+2).at n=23A025169A Chebyshev transform of (1+3x)/(1-3x).at n=23A099858Number of permutations avoiding the patterns {1432,2431,3412,3421,4132,4231,4312,4321}; number of strong sorting class based on 1432.at n=24A111282