121+122+123+...+854
(854×855):2=
730170:2=365085
84+86+88+...+684
(684×685):2=
468540:2=234270
63+66+69+...+537
(537×538):2=
288906=144453
1+4+7+10+.......+541
(541×542):2=
293222:2=146611
1+5+9+11+....+2005
(2005×2006):2=
4022030:2=2011015
3+7+11+15+......+743
(743×744):2=
552792:2=276396
22+25+28+.......+301
(301×302):2=
90902:2=45451
32+39+46+.......+753
(753×754):2=
567762:2=283881
43+51+59+.......+1003
(1003×1004):2=
1007012:2=503506
50+56+62+.......+350
(250×351):2=
122850:2=61425
75+80+85+......+555
(555+556):2=
308580:2=154290
