A201125 Differences between odd powers of 2 and the next smaller square.

1, 4, 7, 7, 28, 23, 92, 7, 28, 112, 448, 1792, 7168, 5503, 22012, 88048, 166831, 296599, 444943, 296863, 1187452, 4749808, 7135951, 4817239, 19268956, 77075824, 118490767, 94338007, 377352028, 1509408112, 3000631951, 5928526807, 11566105231, 21968416927, 39281659711, 59942622847, 45402459391, 181609837564, 726439350256

Offset

1,2

Links

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

Formula

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

Apparently a(n) = A095803(n)/4 for n >= 1. - Hugo Pfoertner, Dec 07 2022

Example

a(1)=2^1-1^1=1, a(2)=2^3-2^2=4, a(3)=2^5-5^2=32-25=7

Mathematica

Table[2^n-Floor[Sqrt[2^n]]^2, {n, 1, 81, 2}] (* Harvey P. Dale, Feb 25 2018 *)

Crossrefs

Cf. A051213, A095803.

Sequence in context: A071529 A349537 A271919 * A154922 A060409 A305740

Adjacent sequences: A201122 A201123 A201124 * A201126 A201127 A201128

Keyword

nonn

Author

Hugo Pfoertner, Nov 27 2011

Status

approved