184045

Appears in sequences

• Numerators of continued fraction convergents to sqrt(369).at n=7A041698
• Number of Catalan objects fixed by four-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).at n=13A079225
• Irregular triangular array: row n gives numbers D, each being the discriminant of the minimal polynomial of a quadratic irrational represented by a continued fraction with period an n-tuple of 1s and 3s.at n=48A246921
• Irregular triangular array: every periodic simple continued fraction CF represents a quadratic irrational (c + f*sqrt(d))/b, where b,c,f,d are integers and d is squarefree. Row n of this array shows the distinct values of d as CF ranges through the periodic continued fractions having period an n-tuple of 1s and 3s.at n=48A246922
• Number of amicable pairs with lesser member at most 2^n.at n=52A290985