67860

Appears in sequences

• Fermat coefficients.at n=11A000972
• a(n) = floor(C(n,6)/7).at n=29A011797
• Number of necklaces with 7 black beads and n-7 white beads.at n=23A032192
• Schoenheim bound L_1(n,7,6).at n=22A036834
• T(n,7), array T as in A051168; a count of Lyndon words; aperiodic necklaces with 7 black beads and n-7 white beads.at n=23A051172
• a(n) =(A001359[n]^2-1)/2.at n=24A117849
• Amicable triples: numbers such that sigma(x) = sigma(y) = sigma(z) = x+y+z, x<y<z. We order these triples according to the common value of sigma. Sequence gives x numbers.at n=13A125490
• 10^n-th number divisible by exactly 5 distinct primes.at n=2A143043
• a(n) = (2*n^3 + 5*n^2 - 7*n)/2.at n=39A162261
• Number of n X 3 1..3 arrays containing at least one of each value, all equal values connected, rows considered as a single number in nondecreasing order, and columns considered as a single number in decreasing order.at n=11A166842
• a(n) = 81*n^2 - 9*n.at n=29A277991
• a(1)=1, a(2)=2; thereafter a(n+1) = Sum_{i=m..n} a(i) where m = (n+1)-k and k is the last digit of a(n), except if k=0, k=1, or k>n then a(n+1) = Sum_{i=1..n} a(i).at n=18A309311
• Oblong composite numbers m such that beta(m) = tau(m)/2 - 1 where beta(m) is the number of Brazilian representations of m and tau(m) is the number of divisors of m.at n=19A326384
• a(n) = n^2*(1+n)*(1+n^2)/4.at n=11A328994
• Numbers that are the sum of six fourth powers in exactly six ways.at n=30A345818