39102

Appears in sequences

• Numbers k such that k | sigma_3(k) - phi(k)^3.at n=22A055697
• Number of line segments connecting exactly 6 points in an n x n grid of points.at n=41A177722
• Fourth accumulation array, T, of the natural number array A000027, by antidiagonals.at n=48A185509
• Number of partitions of n into distinct parts with boundary size 9.at n=39A227566
• Numbers n for which there exists k < n such that A000203(k) = A000203(n) and A007947(k) = A007947(n), where A000203 gives the sum of divisors, and A007947 gives the squarefree kernel of n.at n=5A255335
• The least number k > A255334(n) for which A000203(k) = A000203(A255334(n)) and A007947(k) = A007947(A255334(n)), where A000203 gives the sum of divisors, and A007947 gives the squarefree kernel of n.at n=5A255423
• Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00001011.at n=10A261548
• Expansion of Product_{k>=1} (1 + x^k) / (1 - x^k)^k.at n=16A262803
• Indices of primes in A022567.at n=6A285221
• Triples of practical numbers: numbers n such that n-2, n, n+2 are all practical numbers.at n=38A287682
• a(n) has exactly (a(n) - n) / 2 partitions with exactly (a(n) - n) / 2 prime parts.at n=34A299732
• a(n) = 27*n^2 - 51*n + 24, n>=1.at n=38A304836
• a(n) = (2*n^4 - 6*(-1)^n*n^2 - 2*n^2 + 3*(-1)^n - 3)/96.at n=37A350050
• Fourth Lie-Betti number of a path graph on n vertices.at n=27A362007
• a(n) is the sigma irregularity of the n-th power of a path graph of length at least 3*n.at n=17A363706
• a(n) = Sum_{k=1..n} sigma_2( n/gcd(k,n) ).at n=37A372226