47321

Appears in sequences

• Pell-Lucas numbers: numerators of continued fraction convergents to sqrt(2).at n=13A001333
• NSW numbers: a(n) = 6*a(n-1) - a(n-2); also a(n)^2 - 2*b(n)^2 = -1 with b(n) = A001653(n+1).at n=6A002315
• Interleave denominators (A000129) and numerators (A001333) of convergents to sqrt(2).at n=27A002965
• Representation degeneracies for boson strings.at n=38A005292
• a(n) is the number of unlabeled modular lattices on n nodes.at n=17A006981
• Primitive parts of Pell numbers.at n=25A008555
• Array T(n,k) = number of conjugacy classes of subgroups of index k in free group of rank n, read by antidiagonals.at n=38A057004
• Number of conjugacy classes of subgroups of index 3 in free group of rank n.at n=6A057009
• The next smallest pair of numbers is taken so that a(2n-1)/a(2n) converges to sqrt(2).at n=36A065375
• Number of 12 X n binary arrays with a path of adjacent 1's from top row to bottom row.at n=1A069370
• Product representation of the Pell numbers A000129 and A002203.at n=12A072280
• a(n) is the n-th new record value in A073300.at n=34A073301
• Expansion of (1+x)/(1-2*x-x^2).at n=12A078057
• Series ratios converge alternately to sqrt(2) and 1+sqrt(1/2).at n=25A082766
• a(1) = 1, a(2) = 2; a(2*k) = 2*a(2*k-1) - a(2*k-2), a(2*k+1) = 4*a(2*k) - a(2*k-1).at n=12A084068
• Expansion of e.g.f.: cosh(sqrt(2)*x)*(1+exp(x)).at n=13A088014
• Expansion of -x*(1+x+x^2+x^4)/(-1+2*x^3+x^6).at n=37A092550
• Composite NSW numbers.at n=2A094666
• a(n) = (a(n-1) mod 2)*a(n-1) + a(n-2) with a(0)=0, a(1)=1.at n=40A097564
• a(n) = (a(n-1) mod 2)*a(n-1) + a(n-2) with a(0)=0, a(1)=1.at n=38A097564