1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 pattern
1+2+3+4+5 1+2+3+4+5+6+7+8+9+10 formula 1+2+3+4+5+6+7+8+9+10 calculator 1+2+3+4+5+6+7+8+9+10 answer 1+2+3+4+5 to 100 1+2+3+4 1+2+3+4 -1/12 1+2+3+4+5+6 to 100 1+2+3+4+5+6+7+8+9 equation through 100 1+2+3+4+5 -1/12 1+2+3+4+n -1/12