18700

Appears in sequences

• Sum of 7th powers: 1^7 + 2^7 + ... + n^7.at n=4A000541
• a(n) = 1^n + 2^n + 3^n + 4^n.at n=7A001551
• Numbers that are the sum of 4 positive 7th powers.at n=20A003371
• 10-gonal (or decagonal) pyramidal numbers: a(n) = n*(n + 1)*(8*n - 5)/6.at n=24A007585
• Positive numbers k such that k and 4*k are anagrams in base 9 (written in base 9).at n=26A023081
• a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t(n)=2*n+1 (odd numbers).at n=46A023865
• a(n) = dot_product(n,n-1,...2,1)*(5,6,...,n,1,2,3,4).at n=39A026060
• Numbers having four 4's in base 8.at n=13A043440
• Triangle T(n,k) giving the number of simple matroids of rank k on n labeled points (n >= 2, 2 <= k <= n).at n=17A058720
• Number of simple matroids of rank 4 on n labeled points.at n=3A058722
• prime(2n) + prime(n) == 0 (mod n).at n=20A066896
• Numbers k such that k+1, k^2+1 and k^4+1 are primes.at n=41A070325
• One sixth area of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.at n=3A089550
• Integers that are Rhonda numbers to more than one base.at n=38A100988
• Row sums of triangle A115237.at n=29A115238
• Expansion of x/((1-x)^2(1+x-x^3-x^4-x^5-x^6-x^7+x^9+x^10)).at n=48A143611
• Number of line segments connecting exactly 6 points in an n x n grid of points.at n=34A177722
• Triangle T(n,k) = sum of the k first n-th powers.at n=32A215083
• Numbers which are the sums of consecutive seventh powers.at n=10A217847
• Even, nonzero decagonal pyramidal numbers.at n=11A218331