207480

Appears in sequences

• Denominators of Cauchy numbers of second type (= Bernoulli numbers B_n^{(n)}).at n=37A002790
• Denominators of continued fraction convergents to sqrt(496).at n=15A041947
• Numbers k such that phi(k) < k/5.at n=25A066765
• First differences of A069474, successive differences of (n+1)^6-n^6.at n=22A069475
• At these values of k, the 1st, 2nd, 3rd and 4th cyclotomic polynomials all give prime numbers.at n=15A070025
• Numbers k such that k-1, k+1, k^2+1 and k^4+1 are all prime numbers.at n=17A070156
• Numbers that can be expressed as the difference of the squares of primes in exactly fifteen distinct ways.at n=0A092011
• Least number that can be expressed as the difference of the squares of primes in exactly n distinct ways.at n=14A092204
• Numbers with prime factorization p*q*r*s*t*u^3 (where p, q, r, s, t, u are distinct primes).at n=4A190378
• Triangle of numerators of coefficients of the polynomial Q^(3)_m(n) defined by the recursion Q^(3)_0(n)=1; for m>=1, Q^(3)_m(n) = Sum_{i=1...n} i^3*Q^(3)_(m-1)(i).at n=29A202717
• Numbers n such that the multiplicative group modulo n is the direct product of 7 cyclic groups.at n=4A272597
• Number of 2 X 2 matrices with entries in {0,1,...,n} and odd determinant with no entry repeated.at n=28A279483
• Least k > 1 such that all divisors of (k^n-1)/(k-1) are == 1 (mod n).at n=23A298076
• a(n) is the smallest k such that A319100(k) = A025610(n).at n=35A307162
• Positive integers that have a record number of divisors in Eisenstein integers.at n=38A323392
• Denominators of higher order Bernoulli numbers.at n=18A332666
• Take the solution to Pellian equation x^2 - 8*n*y^2 = 1 with smallest positive y and x >= 0; sequence gives a(n) = y, or 0 if n is twice a positive square. A368340 gives values of x.at n=61A368339
• Numbers whose infinitary divisors have a mean infinitary abundancy index that is larger than 2.at n=19A374788