26271

Appears in sequences

• a(n) is least k such that k and 6k are anagrams in base n (written in base 10).at n=21A023098
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 12.at n=28A031690
• Number of n-bead necklace structures using exactly two different colored beads.at n=19A056295
• a(n) = n*(6*n^2 - 7*n + 3)/2.at n=21A071230
• Numbers k such that k concatenated with k+3 gives the product of two numbers which differ by 5.at n=7A116179
• Numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 3.at n=6A116205
• G.f.: A(x) = 1 + x*(A_2)^3; A_2 = 1 + x^2*(A_3)^3; A_3 = 1 + x^3*(A_4)^3; ... A_n = 1 + x^n*(A_{n+1})^3 for n>=1 with A_1 = A(x).at n=27A132330
• a(n) = 36*n^2 + n.at n=26A157324
• a(n) = 729*n^2 + 27.at n=6A158645
• G.f.: exp( Sum_{n>=1} A119616(n)*x^n/n ) where A119616(n) = (sigma(n)^2 - sigma(n,2))/2.at n=26A201825
• Expansion of Sum_{n>=1} ((n-1) * q^(n*(n+1)/2) / Product_{k=1..n} (1 - q^k)).at n=54A218074
• Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000011 or 00001011.at n=9A260494
• Triangle read by rows, 1 <= k <= n: T(n,k) = non-isomorphic colorings of a toroidal n X k grid using exactly two colors under translational symmetry and swappable colors.at n=13A294791
• Numbers k such that k-1, k and k+1 are all composite with four, five and six (not necessarily distinct) prime factors respectively.at n=3A342246