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A088581
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Numbers of the form n*x^n + (n-1)*x^(n-1) + . . . + x + 1 for x=3.
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0
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1, 4, 22, 103, 427, 1642, 6016, 21325, 73813, 250960, 841450, 2790067, 9167359, 29893558, 96855124, 312088729, 1000836265, 3196219036, 10169787838, 32252755711, 101988443731, 321655860994, 1012039172392, 3177332285413
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Sum of reciprocals = 1.308346570619799777189561356..
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FORMULA
| 1/4 * [(6n-3)3^n + 7].
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EXAMPLE
| 3*3^3 + 2*3^2 + 3 + 1 = 103
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PROG
| (PARI) trajpolypn(n1, k) = { s=0; for(x1=0, n1, y1 = polypn2(k, x1); print1(y1", "); s+=1.0/y1; ); print(); print(s) } polypn2(n, p) = { x=n; y=1; for(m=1, p, y=y+m*x^m; ); return(y) }
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CROSSREFS
| Sequence in context: A079272 A197667 A007901 * A017970 A099013 A184510
Adjacent sequences: A088578 A088579 A088580 * A088582 A088583 A088584
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KEYWORD
| nonn
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AUTHOR
| Cino Hilliard (hillcino368(AT)gmail.com), Nov 20 2003
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