We've had discussions about clever ways to apply an alternating gerund monadically, but I don't think we found (or I didn't remember) the built in natural way before...
for this number series https://en.wikipedia.org/wiki/Pentagonal_number_theorem, 1 2 5 7 12 15 22 26 35 40 51 57 70 77 92 100 a partition counting function needs to turn the series into , _2 +`-\ Pentagonals 100 1 2 _5 _7 12 15 _22 _26 35 40 _51 _57 70 77 _92 _100 , _1 ]`-\ i.5 0 _1 2 _3 4 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
