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Search: id:A131196
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| A131196 |
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Numbers n such that 1 + S(n) = 0, where S(n) = (S(n-1) + A000040(n))*(-1)^n; S(0)=0, n=>1. |
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+0
2
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| 22, 38, 200, 302, 468, 560, 1186, 1208, 2006, 2026, 2106, 23698, 23716, 25968, 25990, 26706, 48316, 311888, 311914, 311938, 313866, 331540, 332002, 377102, 377634, 377670, 377748, 378428, 378452, 378996, 379026, 379090, 387618, 388140, 389398
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The terms are equal to A130642 for n/2 even (70 terms), and to A130643 for n/2 odd (91 terms).
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EXAMPLE
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S(21)=(..((((0+2)*-1)+3)*1)+5)*-1)+7)*1)+11)*- 1)+13)*1)+...+71)*1)+73)*-1 = -80, 1 + S(22) =1 + (-80 + 79)*1 = 0, hence 22 is a term.
S(37)=(..((((0+2)*-1)+3)*1)+5)*-1)+7)*1)+11)*- 1)+13)*1)+...+151)*1)+157)*-1 = -164, 1 + S(38) =1 + (-164 + 163)*1 = 0, hence 38 is a term.
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MATHEMATICA
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S=0; a=0; Do[S=(S+Prime[n])*(-1)^n; If[1+S==0, a++; Print[a, " ", n]], {n, 1, 10^8, 1}]
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CROSSREFS
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Cf. A130642, A130643, A008347, A066033, A000040.
Sequence in context: A039373 A043196 A043976 this_sequence A075217 A116658 A026061
Adjacent sequences: A131193 A131194 A131195 this_sequence A131197 A131198 A131199
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KEYWORD
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nonn
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AUTHOR
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Manuel Valdivia (mvaldivia(AT)ugr.es), Sep 26 2007
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