22152

Appears in sequences

• Numbers whose set of base-9 digits is {3,4}.at n=32A032833
• Numbers having four 3's in base 9.at n=20A043468
• Numbers n such that the arithmetic, geometric and harmonic means of phi(n) and sigma(n) are all integers.at n=15A065146
• a(n) = (4*n^3 + 6*n^2 + 8*n + 6)/3.at n=25A100504
• a(n) = floor((x^n - (1-x)^n) / (2x-1) +.5) where x = (sqrt(6)+1)/2 (and hence 2x-1 = sqrt(6)).at n=19A136424
• Numbers k such that sigma(k) = 9*phi(k).at n=9A163667
• Numbers m such that the GCD of the x's that satisfy sigma(x) = m is 5.at n=1A241650
• Indices of primes in A214829.at n=24A243622
• Number of (n+1)X(7+1) arrays of permutations of 0..n*8+7 with each element having directed index change 0,1 0,-1 -2,0 or 1,1.at n=3A264877
• T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having directed index change 0,1 0,-1 -2,0 or 1,1.at n=48A264878
• Number of (4+1)X(n+1) arrays of permutations of 0..n*5+4 with each element having directed index change 0,1 0,-1 -2,0 or 1,1.at n=6A264881
• Triangle T(n,m) (n >= 1, 0 <= m < n) giving coefficients of (n-1)! P_n, where P_n is the polynomial formula for row n of A213086.at n=52A273528
• Integers n such that sigma(n)/phi(n) is a perfect square.at n=23A293391
• Number of pentagons in the graph formed by drawing the lines connecting any two of the 2*(n+2) perimeter points of a 3 X (n+1) rectangular grid of points (or equally, a 2 X n grid of squares).at n=43A332608
• Number of fault-free tilings of a 3 X n rectangle with squares and dominoes.at n=13A334396
• Number of integer partitions of n of odd rank.at n=41A340692
• G.f. satisfies A(x) = exp( Sum_{k>=1} A(x^k) * x^k/(k * (1 + x^k)^2) ).at n=43A363567
• a(n) is the sum of distinct sums of all subsets with two or more elements of {1, 2, ..., n}.at n=20A375764