33271

Appears in sequences

• Composite numbers whose prime factors have no digits other than 7's and 9's.at n=15A036324
• Composite numbers n such that the sum of divisors of n, sigma(n), divided by the number of divisors, d(n) and sigma(n) minus n are both rational squares.at n=9A049226
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (0, 1, -1), (0, 1, 1), (1, 0, 1)}.at n=8A150538
• Positive numbers y such that y^2 is of the form x^2+(x+2401)^2 with integer x.at n=18A157247
• Numbers k such that k and k+1 are both of the form p*q^3 where p and q are distinct primes.at n=27A215173
• Numbers with 3 or more prime factors (with multiplicity) such that every concatenation of their prime factors is prime.at n=35A217264
• Numbers with 4 or more prime factors (with multiplicity) such that every concatenation of their prime factors is prime.at n=1A217265
• Numbers k dividing u(k), where the Lucas sequence is defined u(i) = u(i-1) - 2*u(i-2) with initial conditions u(0)=0, u(1)=1.at n=7A228439
• Number of (n+1)X(n+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.at n=8A250652
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 421", based on the 5-celled von Neumann neighborhood.at n=36A272051
• Numbers n such that both phi(n) and psi(n) are perfect squares.at n=38A291549
• a(n) is the smallest nonnegative integer m such that the integer part of tan(m) is equal to n.at n=27A327788
• Starts of runs of 3 consecutive numbers that have an equal number of unitary and nonunitary prime divisors (A348097).at n=29A348099
• Three-column array giving list of primitive triples for integer-sided triangles with A < B < C < 2*Pi/3 and such that FA, FB, FC are also integers where F is the Fermat point of the triangle.at n=28A352360