A262213 Minimum number of 3's such that n*[n; 3, ..., 3, n] = [x; ..., x] for some x, where [...] denotes simple continued fractions.

2, 1, 5, 2, 5, 7, 5, 5, 2, 3, 5, 12, 23, 5, 11, 7, 5, 19, 5, 7, 11, 21, 5, 14, 38, 17, 23, 6, 5, 31, 23, 3, 23, 23, 5, 18, 59, 25, 5, 6, 23, 41, 11, 5, 65, 47, 11, 55, 14, 7, 77, 25, 17, 11, 23, 19, 20, 11, 5, 29, 95, 23, 47, 38, 11, 67, 23, 21, 23, 71, 5, 36, 56, 29, 59, 7, 77, 25, 11, 53

Offset

2,1

Comments

Sequence A213892 lists fixed points of this sequence.

Links

Table of n, a(n) for n=2..81.

Prog

(PARI) cf(v)={t=v[#v]; forstep(i=#v-1, 1, -1, t=v[i]+1/t); t}
A262213(n, d=3)=for(k=1, 9e9, (c=contfrac(cf(vector(k+2, i, if(i>1&&i<k+2, d, n)))*n))[1]==c[#c]&&return(k))

Crossrefs

Cf. A213648, A262212 - A262220, A213900, A262211; A000057, A213891 - A213899, A261311.

Sequence in context: A298212 A087620 A253809 * A379219 A178913 A142721

Adjacent sequences: A262210 A262211 A262212 * A262214 A262215 A262216

Keyword

nonn

Author

M. F. Hasler, Sep 15 2015

Status

approved