286903

Appears in sequences

• Lexicographically earliest sequence of pairwise coprime triangular numbers.at n=33A034792
• Pseudoprimes to bases 3 and 7.at n=22A083735
• Odd composites with increasing proportion of nontrivial non-witnesses of compositeness by the Miller-Rabin primality test.at n=12A090659
• Records in A111273.at n=22A113732
• Triangular numbers that are also brilliant (A078972).at n=32A113940
• Hexagonal numbers for which both the sum of the digits and the product of the digits are also hexagonal numbers.at n=29A117064
• Numbers of the form p*q, p and q prime with q=2*p-1.at n=18A129521
• Odd numbers with increasing numbers of bases to which they are strong pseudoprimes.at n=24A141768
• Indices of records in A165633.at n=22A165761
• Numbers m such that exactly half of the a such that 0<a<m and (a,m)=1 satisfy a^(m-1) == 1 (mod m).at n=37A191311
• Odd non-Carmichael numbers with increasing numbers of bases to which they are pseudoprimes.at n=34A194946
• Fermat pseudoprimes n to base 3 for which sqrt(8*n + 1) is an integer.at n=24A217841
• Squarefree numbers (from A005117) with prime divisors in a 2p-1 progression.at n=20A231814
• Record values in A265388.at n=21A265395
• Odd numbers > 1, not powers of primes, for which A326147(n) is equal to abs(A326146(n)).at n=25A326148
• Odd composite numbers k for which the number of witnesses for strong pseudoprimality of k equals phi(k)/4, where phi is the Euler totient function (A000010).at n=13A329759
• Composite numbers whose harmonic mean of their divisors that are larger than 1 is an integer.at n=41A335267
• a(n) = (m(n)^2 + 3)*(m(n)^2 + 7)/32, where m(n) = 2*n - 1.at n=27A336535
• Record values in A346599.at n=24A346601
• Triangular numbers that are emirpimes.at n=12A375385