document.write( "Question 1008641: sum of the numbers of the series:
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Algebra.Com's Answer #627971 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "For k = 1, a1 =   6 =   1+5 = 4^0+5 \r\n" );
document.write( "For k = 2, a2 =   9 =   4+5 = 4^1+5\r\n" );
document.write( "For k = 3, a3 =  21 =  16+5 = 4^2+5\r\n" );
document.write( "For k = 4, a4 =  69 =  64+5 = 4^3+5\r\n" );
document.write( "For k = 5, a5 = 261 = 256+5 = 4^4+5\r\n" );
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document.write( "For k = n-1, an = 261 = 4^(n-1)+5\r\n" );
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document.write( "So we add the sequence \"4%5E0%2B4%5E1%2B4%5E2%2B4%5E3%2B4%5E3%2B%22%22%2A%22%22%2A%22%22%2A%22%22%2B4%5En\"\r\n" );
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document.write( "with the geometric series formula to n terms:\r\n" );
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document.write( "\"S%5Bn%5D\"\"%22%22=%22%22\"\"%28a%5B1%5D%28r%5En-1%29%29%2F%28r-1%29\" with a1 = 1\r\n" );
document.write( "and r = 4.\r\n" );
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document.write( "\"S%5Bn%5D\"\"%22%22=%22%22\"\"%281%284%5En-1%29%29%2F%284-1%29\"\r\n" );
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document.write( "\"S%5Bn%5D\"\"%22%22=%22%22\"\"%281%284%5En-1%29%29%2F3\"\r\n" );
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document.write( "\"S%5Bn%5D\"\"%22%22=%22%22\"\"%284%5En-1%29%2F3\"\r\n" );
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document.write( "Then we must add 5 to that n times which is the same as adding 5n\r\n" );
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document.write( "Answer:  \"SUM%5Bn%5D\"\"%22%22=%22%22\"\"%284%5En-1%29%2F3%5E%22%22%2B5n\"\r\n" );
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document.write( "Edwin

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