[seqfan] A permutation with chunks, sums and division

Eric Angelini Eric.Angelini at kntv.be
Fri Nov 28 17:11:56 CET 2014

Hello SeqFans,

Put a < : > immediately after the 1st integer, then (from there) another < : >
after 2 integers, then after 4 integers, then after 3 integers, etc. (those
marks are placed according to the sequence S itself):


We see now a succession of :chunks: -- where the sum of the integers in each
chunk is divisible by the first integer of the said chunk (T=sum; D=division):

T=1  6     21     32         60               122            146+a
D=  6/2   21/3   32/8       60/10            122/16        146+a /21

As S must always be extended with the smallest available integer not yet present
in S, we see (at the end of the present sequence) that the smallest available 
< a >, must be = 43.

S is the lexico-first permutation of the integers >0 with this property.


More information about the SeqFan mailing list