login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A214034
The apparition sequence for 2,4 continued fractions.
1
1, 2, 3, 3, 5, 7, 7, 2, 3, 5, 11, 13, 7, 11, 15, 8, 5, 8, 3, 23, 5, 21, 23, 19, 13, 8, 7, 27, 11, 31, 31, 5, 17, 7, 11, 37, 17, 41, 7, 20, 23, 20, 11, 11, 21, 45, 47, 7, 19, 8, 27, 51, 17, 11, 7, 8, 27, 14, 11, 61
OFFSET
1,2
COMMENTS
See A214030 for an explanation. There seems to be no corresponding linear recurrence.
PROG
(PARI)
{a24(n)=local(t, m=1, s=[n]); if(n<2, 0, while(1,
if(m%2, s=concat(s, 2), s=concat(s, 4));
t=contfracpnqn(concat(s, n));
t=contfrac(n*t[1, 1]/t[2, 1]);
if(t[1]<n^2||t[#t]<n^2, m++, break)); m)};
//To print out the sequence A214034//
for(i=2, 70, print1(a24(i), ", "))
CROSSREFS
Cf. A214030.
Sequence in context: A086786 A211890 A231406 * A343224 A047844 A081217
KEYWORD
nonn
AUTHOR
Art DuPre, Jul 21 2012
STATUS
approved