4194302

Appears in sequences

• a(n) = 2^n - 2.at n=22A000918
• a(2*n) = 3*2^n - 2; a(2*n+1) = 2^(n+2) - 2.at n=41A027383
• Number of palindromes of length n using exactly two different symbols.at n=42A056453
• Number of primitive (aperiodic) palindromes using a maximum of two different symbols.at n=42A056458
• Number of primitive (aperiodic) palindromes using exactly two different symbols.at n=42A056463
• Number of primitive (period n) periodic palindromes using exactly two different symbols.at n=42A056498
• Numerator of the expected time to finish a random Tower of Hanoi problem with n disks using optimal moves.at n=21A060590
• Biased numbers: n such that all terms of the sequence f(n), f(f(n)), f(f(f(n))), ..., 1, where f(k) = floor(k/2), are odd.at n=40A066880
• a(0) = 1; a(n) = a(n-1)+1 if n is even, otherwise a(n) = 2*a(n-1).at n=41A075427
• Largest term in periodic part of continued fraction expansion of square root of -1+2^n or 0 if -1+2^n is square.at n=41A077625
• Expansion of (1-x+2x^2)/((1-x)*(1-2x)).at n=21A095121
• Values of k such that the total number of 1's in the binary expansions of the first k integers is a multiple of k.at n=38A095376
• Fundamental difference of Ulam 1-additive sequence starting U(2,2n+1).at n=9A100730
• Number of palindromes (in base 8) below 8^n.at n=13A117867
• a(0) = 1, a(n) = (-1)^n*(2-2^(n-1)) for n>0.at n=23A122959
• Row sums of triangle A134066.at n=20A134067
• a(n) = a(n-1) + 2a(n-2).at n=22A135440
• a(2*n) = 2*(2*4^(n-1)-1) and a(2*n-1) = 2*4^(n-1)-1.at n=22A140253
• a(n) is the period of a 2 X 4n rectangular oscillator in the 2 X 2 (B36/S125) Life-like cellular automaton.at n=23A160657
• Number of length n+2 0..1 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.at n=20A250554