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A372804
Decimal expansion of Sum_{k >= 1, A034887(k) even} 1/2^k.
2
1, 1, 1, 2, 1, 9, 5, 1, 2, 1, 9, 5, 1, 2, 1, 9, 5, 1, 2, 1, 9, 5, 1, 2, 1, 9, 5, 1, 2, 2, 0, 4, 9, 7, 3, 0, 9, 2, 2, 7, 9, 8, 3, 3, 1, 2, 3, 0, 3, 3, 4, 3, 4, 2, 6, 8, 9, 1, 3, 7, 9, 4, 3, 8, 2, 9, 8, 8, 2, 3, 5, 9, 1, 3, 9, 7, 7, 2, 6, 2, 4, 1, 7, 4, 7, 8, 6, 6, 4, 2
OFFSET
0,4
LINKS
J. M. Borwein and P. B. Borwein, Strange Series and High Precision Fraud, The American Mathematical Monthly, Vol. 99, No. 7 (1992), pp. 622-640.
FORMULA
Approximately 114/1025, correct to 30 digits: see Example 4.2 (b) in Borwein and Borwein (1992), p. 634.
EXAMPLE
0.1112195121951219512195121951220497309227983312303343426891...
MATHEMATICA
First[RealDigits[Sum[If[OddQ[IntegerLength[2^k]], 0, 1/2^k], {k, 350}], 10, 100]]
CROSSREFS
Sequence in context: A293417 A295737 A021086 * A298521 A177972 A011136
KEYWORD
nonn,cons
AUTHOR
Paolo Xausa, May 13 2024
STATUS
approved