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URL: https://oeis.org/A152720

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A152720

A prime-based vector recursion: a(n)={Prime[n],Prime[n-1],-Prime[n-2],...,-1,-1}.

0

-1, 1, -1, 3, -1, -1, 5, -3, -1, -1, 7, -5, -3, -1, -1, 11, -7, -5, -3, -1, -1, 13, -11, -7, -5, -3, -1, -1, 17, -13, -11, -7, -5, -3, -1, -1, 19, -17, -13, -11, -7, -5, -3, -1, -1, 23, -19, -17, -13, -11, -7, -5, -3, -1, -1, 29, -23, -19, -17, -13, -11, -7, -5, -3, -1, -1

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

0,4

COMMENTS

Row sums are: {-1, 0, 1, 0, -3, -6, -15, -24, -39, -54, -71,...}

LINKS

Table of n, a(n) for n=0..65.

FORMULA

a(n)={Prime[n],Prime[n-1],-Prime[n-2],...,-1,-1}.

EXAMPLE

{-1},

{1, -1},

{3, -1, -1},

{5, -3, -1, -1},

{7, -5, -3, -1, -1},

{11, -7, -5, -3, -1, -1},

{13, -11, -7, -5, -3, -1, -1},

{17, -13, -11, -7, -5, -3, -1, -1},

{19, -17, -13, -11, -7, -5, -3, -1, -1},

{23, -19, -17, -13, -11, -7, -5, -3, -1, -1},

{29, -23, -19, -17, -13, -11, -7, -5, -3, -1, -1}

MATHEMATICA

b[0] = {-1}; b[1] = {1, -1};

b[n_] := b[n] = Join[{Prime[n ]}, {-b[n - 1][[ 1]]}, Table[b[n - 1][[i]], {i, 2, Length[b[n - 1]]}]];

Table[b[n], {n, 0, 10}]; Flatten[%]

CROSSREFS

Sequence in context: A280533 A229288 A181109 * A131247 A114278 A134836

Adjacent sequences: A152717 A152718 A152719 * A152721 A152722 A152723

KEYWORD

tabl,sign

AUTHOR

Roger L. Bagula, Dec 11 2008

STATUS

approved