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A088579
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Primes of the form n*x^n + (n-1)*x^(n-1) + . . . + x + 1 for x=2.
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0
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3, 11, 643, 425987, 1909526242005090307, 23022895558580442706439279569724601504895911302154162237586282577237116573795771448387257510093253287303723617020373843853928820634751104133890051
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OFFSET
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1,1
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COMMENTS
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Sum of reciprocals = 0.4257999816852453227652727311..
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LINKS
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EXAMPLE
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2*2^2 + 1*2 + 1 = 11
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MATHEMATICA
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Select[Table[1+Sum[k 2^k, {k, n}], {n, 1000}], PrimeQ] (* T. D. Noe, Nov 15 2006 *)
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PROG
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(PARI) trajpolyp(n1, k) = { s=0; for(x1=0, n1, y1 = polypn2(k, x1); if(isprime(y1), print1(y1, ", "); s+=1.0/y1; ) );
polypn2(n, p) = { x=n; y=1; for(m=1, p, y=y+m*x^m; ); return(y) }
trajpolyp(10, 2)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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