[seqfan] Four, Nine, Eighteen, ...

[Eric Angelini]

Hello SeqFans,
the last letter of (the English) integer A
is the Ath letter in the seq.

FOUR,NINE,EIGHTEEN,ONEHUNDRED,
SEVEN,SIXTEEN,TWENTYFOUR,
TWENTYFIVE,FORTYONE,FIFTYONE,
EIGHTY,SEVENTYFIVE,THREEHUNDRED,
NINETYONE,NINETYFOUR,NINETYFIVE,
ONEHUNDREDEIGHT,ONEHUNDREDELEVEN,
ONEHUNDREDTWELVE,ONEHUNDREDTHIRTEEN,
ONEHUNDREDFIFTEEN,ONEHUNDREDTHIRTYFIVE,
ONEHUNDREDFORTYONE,...

A = 4,9,18,100,7,16,24,25,41,51,80,75,
300,91,94,95,108,111,112,113,115 135,
141,143,179,195,212,214,...

A was always extended with the smallest
integer not yet in A.

The equivalent seq [the FIRST letter
of (the English) integer B is the Bth
letter in the seq.], is infinite too --
but a iota less "fun" to build:

B = 1,4,8,12,13,18,23,31,35,39,75,85,86,105,119,...

Best,
É.