50881

Appears in sequences

• Strong pseudoprimes to base 94.at n=18A020320
• Numbers whose base-15 representation has exactly 5 runs.at n=15A043672
• Base-3 Euler-Jacobi pseudoprimes.at n=26A048950
• Pseudoprimes to bases 3 and 7.at n=9A083735
• Composite numbers n with the property that phi(n) divides (n-1)^2.at n=14A173703
• Product of exactly three distinct primes congruent to 1 mod 8 (A007519).at n=0A185379
• Smallest product of three distinct primes of the form n*k+1.at n=7A193873
• Euler pseudoprimes to base 3: composite integers such that abs(3^((n - 1)/2)) == 1 mod n.at n=31A262051
• Euler pseudoprimes to base 7: composite integers such that abs(7^((n - 1)/2)) == 1 mod n.at n=31A262054
• Least number of the form x^n + y^n that is the sum of two positive squares in exactly n ways (x, y > 0).at n=3A274485
• Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of continued fraction 1/(1 - x/(1 - 2^k*x/(1 - 3^k*x/(1 - 4^k*x/(1 - 5^k*x/(1 - ...)))))).at n=48A290569
• Composite numbers k such that (1 - w)^(k-1) == 1 (mod k) in the ring of Eisenstein integers (w = (-1 + sqrt(3)*i)/2).at n=25A329705
• O.g.f.: 1/(1 - x/(1 - 2^6*x/(1 - 3^6*x/(1 - 4^6*x/(1 - 5^6*x/(1 - 6^6*x/(1 -...))))))), a continued fraction.at n=3A337808
• Array read by descending antidiagonals: A family of generalized Catalan numbers generated by a generalization of Deléham's Delta operator.at n=51A372001
• Composite numbers k == 1, 11 (mod 12) such that 3^((k-1)/2) == 1 (mod k).at n=19A375917
• Centered square numbers which are sphenic numbers.at n=21A380882