A171449 Powers of 2 (A000079) with 1 changed to -1.

-1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824, 2147483648, 4294967296, 8589934592

Offset: 0

Author

Paul Curtz, Dec 09 2009

Keywords

• sign
• easy
• changed

Links

• Index entries for linear recurrences with constant coefficients, signature (2).

Crossrefs

Cf. A000079.

Programs

Mathematica

Join[{-1}, 2^Range[50]] (* Paolo Xausa, Aug 27 2025 *)

Formula

From Stefano Spezia, Aug 26 2025: (Start)

G.f.: -(1 - 4*x)/(1 - 2*x).

E.g.f.: exp(2*x) - 2. (End)

Extensions

Edited by N. J. A. Sloane, Dec 17 2009