66990

Appears in sequences

• Number of exterior points formed by extending diagonals of n-gon in general position.at n=27A005701
• Number of scalars which can be constructed from the Riemann tensor and metric tensor in n dimensions.at n=29A050297
• Products of exactly 6 distinct primes.at n=7A067885
• Numbers k such that Sum_{d divides k} sigma(d)/phi(d) is an integer.at n=31A068991
• Numbers with six distinct prime divisors.at n=8A074969
• First occurrence (*2) of n in A088627 - or - least number that yields n different primes if you factorize it in all possible ways in two factors and add these factors.at n=18A091350
• Partial products of A102926.at n=5A102927
• a(n) = n*(n-1)*(n-2)*(n+3)/12.at n=30A117662
• Numbers k such that 2*k-1, 4*k-1, 6*k-1 and 8*k-1 are primes.at n=31A124487
• a(n) = rad(A143176(n)).at n=28A144361
• Squarefree positive integers of the form u*v*(u^2-v^2) for some integer u,v.at n=31A147779
• Squarefree nonprimes n with a divisor d such that phi(n) divides n+d.at n=33A217741
• Number of n X 2 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=6A230835
• T(n,k)=Number of nXk 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=29A230840
• T(n,k)=Number of nXk 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=34A230840
• Positions of records in A246272.at n=12A246349
• Least positive integer k such that prime(k)-k, prime(k)+k, prime(k*n)-k*n, prime(k*n)+k*n, prime(k)+k*n and prime(k*n)+k are all prime.at n=26A259492
• Numbers k such that usigma(k) >= 3*k, where usigma(k) = sum of unitary divisors of k (A034448).at n=7A285615
• Numbers that appear in A195441 at least once for two consecutive indices.at n=9A286763
• Unitary totient superdeficient numbers: numbers n > 1 such that s(n)/n < s(m)/m for all m < n, where s is the sum of iterated uphi (A047994).at n=11A291174