StevenXClontz’s Twitter Archive—№ 1,997

…in reply to @siwelwerd
@siwelwerd Maybe [n] notation can be abused to get [na_n]. Then you could use \sum_{r=\sum[na_n]}. Looks okay: mathb.in/105267
On twitter.com 2016 Nov 11 Mood -3 🙁