19517

Appears in sequences

• Strong pseudoprimes to base 12.at n=13A020238
• Strong pseudoprimes to base 37.at n=11A020263
• Strong pseudoprimes to base 56.at n=13A020282
• Composite numbers not divisible by 2 or 3 which in base 3 contain their largest proper factor as a substring.at n=20A063132
• Members of A038512 of the form k, k+2, k+6, k+8.at n=30A155511
• Number of Sylvester classes of 1-multiparking functions of length n.at n=6A243688
• 50-gonal numbers: a(n) = 48*n*(n-1)/2 + n.at n=29A261343
• Composite hypotenuses of primitive Pythagorean triangles (A120961) that are not circumdiameters of non-Pythagorean primitive Heronian triangles (A285579).at n=23A329148
• a(1) = 1; for n > 1, a(n) is the smallest unused positive number such that sopfr(|a(n) - a(n-1)|) = sopfr(a(n) + a(n-1)) and Omega(|a(n) - a(n-1)|) = Omega(a(n) + a(n-1)), where sopfr(k) is the sum of the primes dividing k, with repetition.at n=54A370503