114660

Appears in sequences

• a(n) = 2*n * Stirling2(n-1,2).at n=14A052749
• Number of degree-n odd permutations of order exactly 4.at n=10A061138
• Numbers k such that gcd(sigma(k),k) = k/5.at n=16A067237
• Numbers k such that k-1, k+1, k^2+1 and k^4+1 are all prime numbers.at n=10A070156
• Square array T(i,j) = Bernoulli(2i)*Bernoulli(2j) read by antidiagonals: denominators.at n=48A071021
• Square array T(i,j) = Bernoulli(2i)*Bernoulli(2j) read by antidiagonals: denominators.at n=51A071021
• Numbers k such that (k-1, k+1) and (k/2-1, k/2+1) are both pairs of twin primes.at n=16A076504
• Triangle read by rows: T(n,k) = (n+1,k)-th element of (M^4-M)/3, where M is the infinite lower Pascal's triangle matrix, 1<=k<=n.at n=39A096035
• Integers that can be expressed as a product of triangular numbers in 3 different ways.at n=5A110904
• Twin prime averages which are also the sum of the divisors of a triangular number.at n=34A166162
• Binomial convolution of the central Stirling numbers of the second kind.at n=5A187657
• Numbers with prime factorization pqr^2s^2t^2.at n=4A190379
• Number of (w,x,y,z) with all terms in {1,...,n} and w>2x and y>3z.at n=42A212518
• Numbers k for which sigma(k)/k - 4/5 is an integer.at n=3A218427
• Integers k such that numerator and denominator of sigma(k)/k are both prime.at n=17A247086
• Numbers k such that k = rad(k) * sopfr(k), where rad(k) is the squarefree kernel of k and sopfr(k) the integer log of k.at n=39A280935
• Number of 6-cycles in the n X n rook graph.at n=6A288960
• Numbers k for which k * gcd(sigma(k), u) is equal to sigma(k) * gcd(k, u), where u is obtained by shifting the prime factorization of k two steps toward larger primes [with u = A003961(A003961(k))].at n=2A349746
• Numbers k for which k * gcd(sigma(k), A019565(k)) is equal to sigma(k) * gcd(k, A019565(k)).at n=3A351549
• a(n) is the smallest number m with exactly n divisors whose first digit equals the first digit of m.at n=32A357300