document.write( "Question 926763: -1,4,21,56,... ? \n" ); document.write( "

Algebra.Com's Answer #562585 by Edwin McCravy(20056) $\"\"$ $\"About$

You can put this solution on YOUR website!
-1,4,21,56,... ?
\n" ); document.write( "

\r\n" );
document.write( "Divide them by the number of term 1,2,3,4 and see what we get:\r\n" );
document.write( "\r\n" );
document.write( "-1,2,7,14\r\n" );
document.write( "\r\n" );
document.write( "Add 2 to those\r\n" );
document.write( "\r\n" );
document.write( "1,4,9,16\r\n" );
document.write( "\r\n" );
document.write( "Aha!~  The squares!  Now let's start with the squares and go backward\r\n" );
document.write( "\r\n" );
document.write( "We ended up with the squares,\r\n" );
document.write( "\r\n" );
document.write( "So we start with the squares, \r\n" );
document.write( "\r\n" );
document.write( "1,4,9,16\r\n" );
document.write( "\r\n" );
document.write( "Before that we added 2,\r\n" );
document.write( "\r\n" );
document.write( "So we will subtract 2,  \r\n" );
document.write( "\r\n" );
document.write( "-1,2,7,14\r\n" );
document.write( "\r\n" );
document.write( "Before that we divided by the number of term, n\r\n" );
document.write( "\r\n" );
document.write( "So we multiply by the number of term n,  \r\n" );
document.write( "\r\n" );
document.write( "-1,4,21,56\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Plug in n=1,2,3,4,5,...\r\n" );
document.write( "\r\n" );
document.write( "-1, 4, 21, 56, 115, 204, 329, 496, 711, 980, 1309, 1704, 2171, 2716, \r\n" );
document.write( "3345, 4064, 4879, 5796, 6821, 7960, ... \r\n" );
document.write( "\r\n" );
document.write( "Edwin

\n" ); document.write( "

\n" );