65898

Appears in sequences

• 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=21A136424
• a(n) = smallest number that leads to a new cycle under the base-4 Kaprekar map of A165012.at n=15A165029
• a(n) = n*(n+1)*(20*n-17)/6.at n=27A172117
• The Wiener index of the para-polyphenyl chain with n hexagons (see the Dou et al. and the Deng references).at n=13A216112