document.write( "Question 651209: What is the nth number in the sequence?
\n" ); document.write( "1,5,12,22...n \n" ); document.write( "

Algebra.Com's Answer #407579 by MathLover1(20850) $\"\"$ $\"About$

You can put this solution on YOUR website!
your sequence represents $\"pentagonal\"$ numbers are given by $\"n%283n-1%29%2F2\"$ with n=0, +/-1, +/-2, ...\r
\n" ); document.write( "\n" ); document.write( "in your case we will start with $\"n=1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"n%283n-1%29%2F2=1%283%2A1-1%29%2F2=2%2F2=1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"n%283n-1%29%2F2=2%283%2A2-1%29%2F2=5\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"n%283n-1%29%2F2=3%283%2A3-1%29%2F2=12\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"n%283n-1%29%2F2=4%283%2A4-1%29%2F2=22\"$ \n" ); document.write( "

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