178956971

Appears in sequences

• Jacobsthal sequence (or Jacobsthal numbers): a(n) = a(n-1) + 2*a(n-2), with a(0) = 0, a(1) = 1; also a(n) = nearest integer to 2^n/3.at n=29A001045
• a(2*n) = 2*a(2*n-1), a(2*n+1) = 2*a(2*n)-1.at n=29A005578
• a(n) = (2^(2*n + 1) + 1)/3.at n=14A007583
• Number of Barlow packings with group P3(bar)m1(SO) that repeat after 2n-1 layers.at n=29A011950
• Cyclotomic polynomials at x=-2.at n=29A020501
• a(n) = C(n,0) + C(n,3) + ... + C(n,3[n/3]).at n=29A024493
• a(n) = C(n,2) + C(n,5) + ... + C(n, 3*floor(n/3)+2).at n=29A024495
• a(n) = (lcm_{k=0..n} (2^k + 1))/(lcm_{k=0..n-1} (2^k + 1)).at n=28A066845
• Let u(1)=u(2)=u(3)=2, u(n)=(1+u(n-1)u(n-2))/u(n-3); then a(n) is the numerator of u(n).at n=30A076737
• Expansion of 1/((1-x)*(1+2*x)).at n=28A077925
• Triangular array read by rows: row s contains integers of the form (2^s+1)/(2^r+1) in order of increasing r <= s-1.at n=32A079665
• A Jacobsthal number sequence.at n=9A082365
• a(n) = 2^n - A081374(n).at n=27A083322
• Jacobsthal reverse-pair sequence.at n=30A084183
• Generalized mod 3 multiplicative Jacobsthal sequence.at n=29A087462
• Generalized multiplicative Jacobsthal sequence.at n=29A087463
• Generalized Jacobsthal sequence.at n=28A087629
• Pair reversal of Jacobsthal numbers.at n=28A092808
• Expansion of (1 - 2*x + 2*x^2)/((1 - x^2)*(1 - 2*x)).at n=28A097072
• Sylvester-Jacobsthal cyclotomic numbers.at n=28A105603