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A066772 Continued fraction expansion for Sum_{k=1..inf} d(k)/2^k where d(k) are divisors of k, 1<=d<=k. 1
2, 1, 2, 1, 9, 1, 2, 1, 1, 1, 5, 8, 1, 3, 2, 3, 2, 2, 2, 2, 1, 3, 3, 4, 12, 1, 1, 1, 11, 4, 15, 6, 3, 3, 2, 1, 20, 4, 4, 1, 4, 1, 2, 1, 2, 6, 1, 2, 1, 28, 107, 1, 4, 4, 3, 1, 2, 2, 4, 2, 3, 51, 1, 1, 1, 4, 2, 4, 1, 20, 20, 1, 14, 3, 27, 1, 4, 3, 14, 329, 1, 1, 1, 111, 2, 3, 1, 2, 1, 4, 1, 6, 1, 4, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A(1669) accurate to 500 decimal digits

REFERENCES

S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 354-361.

LINKS

Table of n, a(n) for n=1..95.

S. R. Finch, Digital Search Tree Constants

PROG

(PARI) {smv(v)= s=0; for(i=1, matsize(v)[2], s=s+v[i]); s } {A066666(n)= sm=0; for(j=1, n, sm=sm+smv(divisors(j)/2^j)); sm*1.0 }

CROSSREFS

Cf. A066766.

Sequence in context: A146003 A201453 A260897 * A104060 A062347 A124781

Adjacent sequences:  A066769 A066770 A066771 * A066773 A066774 A066775

KEYWORD

nonn,cofr

AUTHOR

Randall L. Rathbun, Jan 16 2002

STATUS

approved

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Last modified September 20 12:42 EDT 2017. Contains 292271 sequences.