405405

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n+1)/3.at n=40A048048
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n+2)/3.at n=40A048081
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n+3)/3.at n=40A048092
• Highly composite odd numbers: odd numbers where d(n) increases to a record.at n=19A053624
• Table related to labeled rooted trees, cycles and binary trees.at n=34A054589
• Numbers k such that 4*k-1, 8*k-1, 16*k-1, 32*k-1 and 64*k-1 are all primes.at n=13A101994
• Triangle read by rows, T(n, k) = Sum_{j=0..n} C(n-j, n-k)*E2(n, j), where E2 are the second-order Eulerian numbers A201637, for n >= 0 and 0 <= k <= n.at n=34A112493
• Oddly superabundant numbers: odd n with sigma(n)/n > sigma(k)/k for all odd k < n.at n=17A119239
• Terms in A038547 where prime signature differs from that of corresponding term in A005179.at n=5A122814
• Numbers n for which 2n-1, 4n-1, 8n-1, 16n-1 and 32n-1 are primes.at n=28A124017
• Numbers n such that 2n-1, 4n-1, 8n-1, 16n-1, 32n-1 and 64n-1 are primes.at n=4A125113
• Smallest odd number with same number of divisors as 3*a(n-1).at n=14A140864
• Numbers with exactly 5 distinct odd prime divisors {3,5,7,11,13}.at n=10A147578
• Smallest number having exactly n divisors of the form 8*k + 7.at n=20A188226
• Values of |G-hat_1(n)|, a sum involving Stirling numbers of the second kind.at n=7A261898
• Least positive integer k with exactly n odd divisors greater than sqrt(2*k).at n=36A281008
• Number of set partitions of [n] having exactly six blocks of size > 1.at n=1A290035
• Irregular triangle read by rows: row n gives numerators of coefficients of polynomials arising from Chebyshev quadrature.at n=46A324123
• Numbers with a record number of divisors whose binary expansion is palindromic.at n=18A330815
• a(n) is the least integer that can be expressed as the difference of two hexagonal numbers in exactly n ways.at n=18A334035