22320

Appears in sequences

• Coordination sequence for MgNi2, Position Ni2.at n=37A009932
• 3rd Bernoulli polynomial evaluated at powers of 2 (multiplied by 6).at n=4A020528
• Numbers k that divide the (left) concatenation of all numbers <= k written in base 19 (most significant digit on left).at n=44A029488
• Numbers k such that phi(k) is equal to A008473(k).at n=14A039779
• E.g.f. x*(1-x)/(1-2*x-x^2+x^3).at n=6A052640
• a(0)=0, for n >= 1, a(n) = (2^(n-1)-1)*n!.at n=6A052665
• Number of strongly connected labeled tournaments on n nodes.at n=5A054946
• a(n) = binomial(2*n,n) mod ((n+1)*(n+2)*(n+3)).at n=28A065345
• a(0) = 1; a(n) = Sum_{1 <= k <= n and k|n} a(n-k).at n=21A067951
• Reverse of largest prime factor of n = smallest prime factor of n+1; a(1)=1.at n=18A071393
• Numbers k that divide tau(k)*sigma(k).at n=34A071707
• Numbers m such that sigma(m)/m is equal to sigma(k)/k for some k being superabundant (A004394).at n=32A073349
• Numbers n such that (i) the largest prime factor of n is not a palindrome and (ii) the sum of the factorials of the digits of n is equal to the largest prime factor of n reversed.at n=13A074301
• Sequence A014486 shown in base 4.at n=27A085185
• Let f(k) denote the largest prime factor of k which is not a palindrome. Sequence gives numbers k such that the sum of the factorials of the digits of k is equal to f(k) reversed.at n=13A111185
• Matrix logarithm of triangle A111536.at n=48A111541
• Positive integers i for which A112049(i) == 8.at n=24A112068
• Number of permutations where for every pair of adjacent elements one element in binary notation has ones at the same or adjacent positions to those of the other element.at n=11A115508
• Expansion of e.g.f. A(x) = 1/(1 - LambertW(-x)^2).at n=6A134095
• Sum of staircase twin primes according to the rule: top * bottom - next top.at n=11A135285