A127252 - OEIS

A127252

Sequence composed of 1 and -1 with the -1's occurring at odious indexed positions given by A091855.

%I #7 Aug 04 2023 04:35:39

%S 1,-1,1,1,-1,1,1,-1,1,1,1,-1,1,-1,1,1,-1,1,1,-1,1,-1,1,1,1,-1,1,1,-1,

%T 1,1,-1,1,1,1,-1,1,-1,1,1,1,-1,1,1,-1,1,1,-1,1,-1,1,1,-1,1,1,-1,1,1,1,

%U -1,1,-1,1,1,-1,1,1,-1,1,-1,1,1,1,-1,1,1,-1,1,1

%N Sequence composed of 1 and -1 with the -1's occurring at odious indexed positions given by A091855.

%t a[n_] := If[EvenQ[IntegerExponent[n, 2]] && OddQ[DigitCount[n, 2, 1]], -1, 1]; Array[a, 100, 0] (* _Amiram Eldar_, Aug 04 2023 *)

%Y Row sums of A127251.

%Y Partial sums are A127255.

%Y Cf. A000069, A091855, A127245.

%K sign,base

%O 0,1

%A _Paul Barry_, Jan 10 2007

%E More terms from _Amiram Eldar_, Aug 04 2023