A206076 - OEIS

A206076

Numerator of p(n,-1/2), where p(n,x) is the polynomial given by A205073.

1, -1, 1, 1, 5, -1, 3, -1, 7, -5, 3, 1, 9, -3, 5, 1, 17, -7, 9, 5, 21, -3, 13, -1, 15, -9, 7, 3, 19, -5, 11, -1, 31, -17, 15, 7, 39, -9, 23, -5, 27, -21, 11, 3, 35, -13, 19, 1, 33, -15, 17, 9, 41, -7, 25, -3, 29, -19, 13, 5, 37, -11, 21, 1, 65

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OFFSET

1,5

COMMENTS

The denominators are given by A053644. (See the Mathematica section.)

LINKS

Table of n, a(n) for n=1..65.

MATHEMATICA

t = Table[IntegerDigits[n, 2], {n, 1, 1000}];

b[n_] := Reverse[Table[x^k, {k, 0, n}]]

p[n_, x_] := t[[n]].b[-1 + Length[t[[n]]]]

Table[p[n, x], {n, 1, 15}]

Table[p[n, x] /. x -> 1, {n, 1, 120}] (* A000120 *)

Table[p[n, x] /. x -> 2, {n, 1, 120}] (* A000027 *)

Table[p[n, x] /. x -> 3, {n, 1, 120}] (* A005836 *)

Table[p[n, x] /. x -> 4, {n, 1, 120}] (* A000695 *)

Table[p[n, x] /. x -> -1, {n, 1, 120}] (* A065359 *)

Table[p[n, x] /. x -> -2, {n, 1, 120}] (* A053985 *)

Numerator[Table[p[n, x] /. x -> 1/2, {n, 1, 120}] ] (* A030101 *)

Numerator[Table[p[n, x] /. x -> -1/2, {n, 1, 120}] ] (* A206076 *)

Denominator[Table[p[n, x] /. x -> -1/2, {n, 1, 120}] ] (* A053644 *)

CROSSREFS

Cf. A205073.

Sequence in context: A155059 A347964 A348498 * A329374 A115638 A342375

Adjacent sequences: A206073 A206074 A206075 * A206077 A206078 A206079

KEYWORD

sign

AUTHOR

Clark Kimberling, Feb 04 2012

STATUS

approved