A201122 Differences between odd powers of 6 and the next smaller square.

2, 20, 32, 95, 3420, 8847, 89927, 494576, 1347932, 48525552, 265807127, 682379927, 3237653360, 52571448911, 356954431580, 1333226567615, 6534477744687, 69394484050880, 10500704463815, 378025360697340, 13608912985104240, 60046182811381232, 227226500274052935, 442409686123219952, 15926748700435918272

Offset: 1

Author

Hugo Pfoertner, Nov 27 2011

Keywords

• nonn

Examples

			a(1)=6^1-2^2=2, a(2)=6^3-14^2=216-196=20, a(3)=6^5-88^2=7776-7744=32
		

Links

• Hugo Pfoertner, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A051217, A200440, A200506

Programs

Mathematica

#-Floor[Sqrt[#]]^2&/@(6^Range[1,51,2]) (* Harvey P. Dale, Aug 12 2012 *)

Formula

a(n)=6^(2*n-1) - floor(sqrt(6^(2*n-1)))^2