873181

Appears in sequences

• Hexagonal numbers (A000384) which are also centered hexagonal numbers (A003215).at n=3A006244
• Records in A111273.at n=30A113732
• Numbers of the form p*q, p and q prime with q=2*p-1.at n=26A129521
• Triangular numbers that are the difference of nonnegative cubes.at n=24A129965
• Terms of A083737 which are not Carmichael numbers (A002997).at n=1A153580
• Intersection of A001567 and A212502.at n=23A212601
• Composite numbers k such that k divides Fibonacci(k+1) or Fibonacci(k-1) and 2^(k-1) == 1 (mod k).at n=14A214434
• Fermat pseudoprimes n to base 3 for which sqrt(8*n + 1) is an integer.at n=36A217841
• Triangular numbers representable as triangular(x)*triangular(y)+1.at n=29A226389
• Squarefree numbers (from A005117) with prime divisors in a 2p-1 progression.at n=28A231814
• Composite numbers k congruent to 5 (mod 8) such that 2^((k-1)/2) mod k = k-1.at n=12A244626
• Record values in A265388.at n=29A265395
• Fermat pseudoprimes to base 2 that are triangular.at n=21A293622
• The "non-residue" pseudoprimes: odd composite numbers n such that b(n)^((n-1)/2) == -1 (mod n), where base b(n) = A020649(n).at n=18A307767
• Fermat pseudoprimes to base 2 that are hexagonal.at n=20A322130
• Odd numbers > 1, not powers of primes, for which A326147(n) is equal to abs(A326146(n)).at n=34A326148
• Numbers that are super pseudoprimes to both bases 2 and 3.at n=12A333130
• Record values in A346599.at n=32A346601
• Odd composite numbers k such that 2^((k-1)/2) == -1 (mod k).at n=13A356638
• The area of the n-th convex honeycomb formed by spirals of incrementing strips of hexagons.at n=14A373081