

A256108


Positions of nonzero digits in binary expansion of Pi.


2



1, 0, 3, 6, 11, 12, 13, 14, 15, 16, 18, 19, 21, 23, 25, 29, 33, 38, 40, 41, 43, 47, 48, 53, 57, 58, 60, 63, 64, 68, 71, 72, 76, 77, 80, 81, 85, 87, 91, 93, 94, 95, 103, 104, 106, 107, 108, 114, 115, 116, 119, 120, 122, 126, 129, 131, 134, 141, 144, 147, 148, 149, 155, 159
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OFFSET

1,3


COMMENTS

Nonzero entries in A004601 (reindexed to start at 1 and ascend).
The binary positions (exponents) are negated for convenience (as is standard practice). By the results of the PiHex project, the number 1,000,000,000,000,060 (for example) eventually appears in this sequence. Submitted on 3/14/15, (decimal) Pi Day.


LINKS

Table of n, a(n) for n=1..64.
Steve Pagliarulo, Stu's pi page: base 2
Colin Percival, PiHex Home Page
Wikipedia, PiHex


FORMULA

Pi = sum {2^(a(n))}.


EXAMPLE

The most significant nonzero binary digit of pi occurs in the 2^1 position. Then there is a digit in the 2^0 position, then the 2^(3) position, etc. Negate the exponents appearing to get this sequence.


CROSSREFS

Cf. A004601, A051480.
Sequence in context: A144562 A102889 A183543 * A028744 A028775 A223910
Adjacent sequences: A256105 A256106 A256107 * A256109 A256110 A256111


KEYWORD

sign,base


AUTHOR

David S. Metzler, Mar 14 2015


STATUS

approved



