106080

Appears in sequences

• Eighth column of quadrinomial coefficients.at n=12A001919
• First element r of (-1)sigma sociable triple (r,s,t): s=(-1)sigma(r), t=(-1)sigma(s), r=(-1)sigma(t), where if x=Product p(i)^r(i), then (-1)sigma(x)=Product(-1+(Sum p(i)^s(i), s(i)=1 to r(i))).at n=28A049057
• Numbers that can be expressed as the difference of the squares of primes in exactly seven distinct ways.at n=29A092003
• Eighth column (m=7) of (1,4)-Pascal triangle A095666.at n=12A095670
• Triangle T(n,k), 1<=k<=n, read by rows given by T(n,k) = A003266(n)/A000045(k).at n=43A121284
• a(n) = 1 + prime(n) + prime(n)^2 + prime(n)^3.at n=14A131991
• Numbers with prime factorization pqrst^5.at n=11A190383
• a(n) = (47^n - 1)/46.at n=4A218750
• Numbers m such that b^sigma(m) == b^phi(m) == b^numdiv(m) == b^m (mod m) for every integer b.at n=40A277173
• Totient numbers (A002202) of the form 1 + k + k^2 + k^3 +...+ k^i (i > 1, k > 1).at n=24A282090
• Numbers m having greatest prime power divisor d such that d is smaller than the difference between m and the largest prime smaller than m and d is smaller than the difference between m and twice the largest prime smaller than m/2.at n=21A290290
• Number of (7-n)-faces of the 1_42 polytope.at n=1A321638
• Denominators of the partial alternating sums of the reciprocals of the sum of unitary divisors function (A034448).at n=28A379516
• Expansion of e.g.f. (1/x) * Series_Reversion( x/(1 + x * cos(x))^2 ).at n=6A381521