[seqfan] Digitsum of a(n) is visible in a(n+1)
Eric Angelini
Eric.Angelini at kntv.be
Mon Feb 22 15:37:47 CET 2010
Hello SeqFans,
here is another re-ordering of the Naturals:
The digitsum of a(n) is visible in the smallest
a(n+1) not yet present in S:
S=1,10,11,2,12,3,13,4,14,5,15,6,16,7,17,8,18,
9,19,100,21,23,25,27,29,111,30,31,24,26,28,
101,20,22,34,37,102,32,35,38,112,40,41,45,
49,113,50,51,46,103,...
... this is computed by hand -- and fun to do!
---
The 'equivalent' seq. is much harder to write:
"Digitsum of a(n) is visible in a(n-1)", or (bet-
ter), "a(n) shows the digitsum of the smallest
a(n+1) not yet present in T":
T=1,10,19,9,18,8,17,7,16,6,15,5,14,4,13,3,12,2,
11,29,20,101,28,26,24,22,110,37,21,...
More headaches than fun with this one!
Best,
É.
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