Hello Math-Fun Instead of writing: 1+2+3+4+5+6+7+8+9+10+11+12+13 +14+15+16+17+18+19+20+21+22+23 +24+25+... I could’ve written the « shortcut »: 3+7+11+24+46+62+37+41+94+... as 3=1+2 7=3+4 11=5+6 24=7+8+9 46=10+11+12+13 62=14+15+16+17 37=18+19 41=20+21 94=22+23+24+25 ... The terms 3,7,11,24,46,62,37,41,94,... are numbers that can be expressed as the sum of k>1 consecutive integers _in only one way_ (they belong to A038550). The terms were always chosen to be the smallest one that could belong to the « shortcut » sequence. One needs to backtrack sometimes as some chunks of consecutive integers cannot be « shortcut » (like the chunk that starts with 16+17+18... if I’m right). This « backtrack » remark applies to the lexicographically earliest « shortcut » tentative: 3,7,11,24,46,29,... which seems impossible to extend. Best, É. Catapulté de mon aPhone