A139356 Sequence describing the positions of the consonants when the sequence is written in French (version 1).

4, 1, 5, 8, 9, 11, 12, 13, 16, 17, 20, 22, 23, 25, 28, 30, 31, 34, 36, 39, 41, 43, 44, 46, 47, 48, 50, 51, 52, 53, 55, 56, 57, 58, 61, 62, 64, 65, 66, 67, 68, 71, 72, 74, 75, 76, 77, 79, 80, 81, 83, 84, 85, 86, 89, 90, 91, 93, 94, 96, 97, 99, 100, 103, 105

Offset: 1

Author

N. J. A. Sloane (based on Angelini's article), Jun 08 2008

Keywords

• nonn
• word
• easy

Comments

The sequence depends on how the initial terms are selected - see the Angelini article for the precise definition.

Links

• Eric Angelini, Jeux de suites, in Dossier Pour La Science, pp. 32-35, Volume 59 (Jeux math'), April/June 2008, Paris.

Crossrefs

Cf. A139212, A139357, A139358, A167507.

Programs

PARI

lista(n) = frconspos([4])(n)
frconspos(startseq) = n -> {
my(consonants = Vec("bcdfghjklmnpqrstvwxyz"), charoffset = 0, seqindex = #startseq + 1, seq = Vec(startseq, n));
if(n <= #startseq, seq[1..n], for(i = 1, n, my(thisfrench = Vec(strchr([c|c<-Vecsmall(French(seq[i])), c>96])), consonantindexes = select(x->setsearch(consonants, x), thisfrench, 1));
for(j = 1, #consonantindexes, if(#select(I -> I == consonantindexes[j] + charoffset, startseq) == 0, if(seqindex + j - 1 <= n, seq[seqindex] = consonantindexes[j] + charoffset; seqindex++)));
charoffset += #thisfrench);
seq)}
/* see A167507 for French() */
\\ Tyler Busby, Dec 31 2022

Extensions

a(12) corrected and more terms from Tyler Busby, Dec 31 2022