A234605 a(n+1) is next smallest cube ending with a(n), initial term is 0.

0, 1000, 1331000, 1003303631331000, 1000000003003300003006603631003303631331000

Offset: 1

Author

Derek Orr, Dec 28 2013

Keywords

• nonn
• base

Comments

a(6) is too large to include (contains 124 digits).

Crossrefs

Cf. A050646, A050647, A050648, A050650.

Programs

Mathematica

a[n_]:=(Sum[10^((3^i+1)/2),{i,0,n-1}])^3; Array[a,5,0] (* Stefano Spezia, Mar 07 2025 *)

Formula

For n>1, a(n) = 1000*A050646(n-1) = 1000*A050647(n-1)^3.

a(n) = (Sum_{i=0..n-1} 10^((3^i+1)/2))^3. - Max Alekseyev, Jan 07 2015