91625968981
domain: N
Appears in sequences
- a(n) = (4^n - 1)/3.at n=19A002450
- Numerators of coefficients for central differences M_{4}^(2*n).at n=18A002675
- Divisors of 2^38 - 1.at n=6A003544
- Cyclotomic polynomials at x=4.at n=19A019322
- Smallest number to give 2^(2n) in a hailstone (or 3x + 1) sequence.at n=18A054646
- Zsigmondy numbers for a = 4, b = 1: Zs(n, 4, 1) is the greatest divisor of 4^n - 1^n (A024036) that is relatively prime to 4^m - 1^m for all positive integers m < n.at n=18A064080
- A Jacobsthal number sequence.at n=12A082365
- a(n) = -5*a(n-1)-4*a(n-2) with n>1, a(0)=0, a(1)=1.at n=19A084241
- Smallest base-2 Fermat pseudoprime x that has ord(2,x) = n, or 0 if one does not exist.at n=37A086250
- Generalized multiplicative Jacobsthal sequence.at n=38A087463
- Numbers of the form (4^n + 4^(n-1) + ... + 1) + (n mod 2).at n=17A088556
- a(n)=2*(4^n-1)/denominator(B(2n)) where B(k) denotes the k-th Bernoulli number.at n=19A090648
- Column 1 of the array in A107735.at n=36A107732
- a(n) = (2^prime(n) - 8)/24 for n>=2.at n=11A121290
- The Jacobsthal sequence, dropping each third term.at n=25A141355
- a(n) = (4*16^(n-1)-1)/3.at n=9A144864
- a(n) is the number whose binary expansion is A153498(n).at n=18A153497
- Numbers of the form (4^k - 1)/3 whose greatest prime divisor is of the form 2^q - 1 or 2^q + 1.at n=10A187063
- Expansion of x*(1+3*x)/ ( (1-4*x)*(1+x+x^2)).at n=19A191597
- a(n) = (4^A001651(n+1) - 1)/3: numbers (4^k-1)/3 for k > 1, not multiples of 3.at n=11A198586