699051

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=21A001045
• a(2*n) = 2*a(2*n-1), a(2*n+1) = 2*a(2*n)-1.at n=21A005578
• a(n) = (2^(2*n + 1) + 1)/3.at n=10A007583
• Number of Barlow packings with group P3(bar)m1(SO) that repeat after 2n-1 layers.at n=21A011950
• a(n) = C(n,1) + C(n,4) + ... + C(n, 3*floor(n/3) + 1).at n=20A024494
• a(n) = C(n,2) + C(n,5) + ... + C(n, 3*floor(n/3)+2).at n=21A024495
• a(n) = ceiling(2^n/n).at n=23A053638
• a(n) = round( 2^n/n ).at n=23A065482
• 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=22A076737
• Expansion of 1/((1-x)*(1+2*x)).at n=20A077925
• Expansion of 1/(1-x+2*x^2-2*x^3).at n=40A077953
• Expansion of 1/(1-x+2*x^2-2*x^3).at n=41A077953
• Expansion of 1/(1 + x + 2*x^2 + 2*x^3).at n=40A077980
• 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=19A079665
• A Jacobsthal related sequence.at n=5A083228
• Jacobsthal reverse-pair sequence.at n=22A084183
• Generalized Jacobsthal sequence.at n=20A087629
• Pair reversal of Jacobsthal numbers.at n=20A092808
• Least integer value of (1 + 2^n + 3^n + ... + k^n)/(1 + 2 + 3 + ... + k), k > 1.at n=20A094755
• Expansion of (1 - 2*x + 2*x^2)/((1 - x^2)*(1 - 2*x)).at n=20A097072