A059880 - OEIS

A059880

Positions of negative terms in A059876.

8, 32, 33, 34, 35, 36, 64, 65, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 152, 160, 161, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 272, 273, 274, 275

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..53.

MAPLE

negative_terms(A059876); negative_terms := proc(b) local a, i; a := []; for i from 1 to nops(b) do if(b[i] < 0) then a := [op(a), i]; fi; od; RETURN(a); end;

MATHEMATICA

a[n_] := With[{s = Floor[Log[2, n]]}, (-1)^(n+1) + Sum[(-1)^(Floor[n/2^i] + 1)*Prime[i], {i, 1, s}] + If[1 == n, 1, Mod[s + 1, 2]*Prime[s]]];

A059880 = Position[Array[a, 500], _?Negative] // Flatten (* Jean-François Alcover, Mar 07 2016 *)

CROSSREFS

Sequence in context: A300086 A115948 A322056 * A144096 A371444 A127988

Adjacent sequences: A059877 A059878 A059879 * A059881 A059882 A059883

KEYWORD

nonn

AUTHOR

Antti Karttunen, Feb 05 2001

STATUS

approved