531440

Appears in sequences

• a(n) is the number of permutations w of 1,2,...,n such that both w and w^{-1} are alternating.at n=14A007999
• a(n) = 3^n - 1.at n=12A024023
• a(n) = 9^n-1.at n=6A024101
• a(n+1) = smallest number not containing any digits of a(n), working in base 3.at n=24A030439
• Dirichlet convolution of mu(n) with 3^(n-1).at n=12A034741
• Numbers that are repdigits in base 3.at n=24A048328
• Numbers of the form 3^m - 1 or 2*3^m - 1; i.e., the union of sequences A048473 and A024023.at n=24A062318
• Positive numbers which are one less than a perfect square that is also another power.at n=34A062965
• a(n) = n^phi(n) - 1.at n=8A066916
• a(n) = 0^n + 3^n - 1.at n=12A103453
• Self-convolution omits 1's at positions of triangular numbers less one.at n=37A105613
• Self-convolution of A105613.at n=29A105614
• a(n) = 3^n - (-1)^n.at n=12A105723
• a(1)=1; then successively add 1, divide by 2, add 2 and then total up the last 4 terms.at n=45A112027
• a(n) = n^4 - 1.at n=26A123865
• a(n) = n^6 - 1.at n=8A123866
• a(n) = n^12 - 1.at n=2A123868
• a(n) = 2*A132357(n).at n=11A135263
• Clique number of commuting graph of symmetric group S_n.at n=36A135908
• Clique number of commuting graph of alternating group A_n.at n=36A135909