OFFSET
1,1
COMMENTS
Original name: Numbers n such that n/A259748(n) = 6.
Partial sums give A152746. - Leo Tavares, Jul 29 2023
LINKS
Danny Rorabaugh, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
A259748(a(n))/a(n) = 1/6.
a(n) = 6*A016813(n-1). - Michel Marcus, Jul 18 2015
G.f.: 6*x*(3*x+1)/(x-1)^2. - Alois P. Heinz, Jul 29 2023
MATHEMATICA
A[n_] := A[n] = Sum[a b, {a, 1, n}, {b, a + 1, n}] ; Select[Range[600], Mod[A[#], #]/# == 1/6 & ]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
José María Grau Ribas, Jul 12 2015
EXTENSIONS
Better name from Danny Rorabaugh, Oct 22 2015
STATUS
approved