A104056 - OEIS

%I #8 Jan 23 2023 12:08:18

%S 15,14,5,0,6,9,22,5,0,15,14,5,0,6,15,21,18,0,6,9,22,5,0,26,5,18,15,0,

%T 19,9,24,0,14,9,14,5,0,20,23,15,0,20,23,15,0,6,9,22,5,0,26,5,18,15,0,

%U 15,14,5,0,6,9,22,5,0,15,14,5,0,6,15,21,18,0,6,9,22,5,0,26,5,18,15,0,19,9,24

%N Each number is the rank in the alphabet of a letter (and "0" stands for a space). After substitution one reads (in English): "one five one four five zero six nine two two five zero ..." which is the succession of the digits of the sequence itself: 1 5 1 4 5 0 6 9 2 2 5 0...

%C The only other such sequence starts with: 20,23,15,0,26,5,18,15,0... (which reads "two zero...")

%o Contribution from _M. F. Hasler_, Aug 18 2010: (Start)

%o (PARI) /* helper function */

%o digit2seq(d) = { concat( apply( x->bitand(x,-97), Vec( Vecsmall( Str( [zero,one,two,three,four,five,six,seven,eight,nine][d+1])))),0) }

%o /* compute this sequence to at least Nmin terms. */

%o A104056(Nmin,a=[],pos=1)={ while( Nmin > #a=concat( a, concat( apply( digit2seq, eval( Vec( Str( if( #a, a[pos++ ], 15) )))))),);a}

%o (End)

%Y Cf. A169978.

%Y Cf. A104057 (Same rule, but starting with 20). [From _M. F. Hasler_, Aug 18 2010]

%K base,easy,nonn,word

%O 1,1

%A _Eric Angelini_, Mar 02 2005

%E Typo in sequence corrected by _D. S. McNeil_, Aug 18 2010

%E Extended beyond a(55) by _M. F. Hasler_, Aug 18 2010