31894

Appears in sequences

• Numbers n such that phi(reverse(n)) = sigma(n).at n=12A070835
• a(n) = smallest number m which can be obtained in n ways by subtracting twice a triangular number from a perfect square.at n=20A078714
• Number of binary strings of length n with equal numbers of 0011 and 0101 substrings.at n=17A164174
• Pi function of the primes given in A183194.at n=9A183195
• Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having three distinct values for every i<=n and j<=n.at n=11A211459
• G.f.: A(x) = Sum_{n>=1} a(n)*x^n = x*Product_{n>=1} (1 + a(n)*x^n)/(1 - a(n)*x^n).at n=8A299021
• a(n) is the dot product of the vectors of the first n primes and the next n primes.at n=14A337574