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A205649 Hamming distance between twin primes. 14
2, 1, 2, 1, 1, 1, 2, 3, 1, 2, 1, 1, 2, 6, 1, 2, 4, 1, 1, 3, 2, 2, 4, 1, 1, 1, 3, 1, 1, 2, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 7, 1, 1, 1, 1, 3, 2, 2, 1, 4, 3, 2, 2, 1, 1, 2, 4, 1, 2, 1, 1, 2, 1, 3, 6, 1, 1, 1, 2, 1, 2, 1, 1, 5, 1, 7, 3, 1, 1, 1, 1, 3, 4, 5, 2, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Twin primes for which a(n)=1 are in A122565.

Conjecture: The sequence is unbounded.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

FORMULA

A001359(n) == -1 (mod 2^a(n)).

MATHEMATICA

nn = 1000; ps = Prime[Range[nn]]; t = {}; Do[If[ps[[n]] + 2 == ps[[n + 1]], AppendTo[t, ps[[n]]]], {n, nn - 1}]; Table[b2 = IntegerDigits[t[[k]] + 2, 2];  b1 = IntegerDigits[t[[k]], 2, Length[b2]]; Total[Abs[b1 - b2]], {k, Length[t]}] (* T. D. Noe, Jan 30 2012 *)

CROSSREFS

Cf. A205510, A001097, A001359, A006512, A205302, A205511, A205533.

Sequence in context: A140816 A029433 A088203 * A176510 A061342 A104639

Adjacent sequences:  A205646 A205647 A205648 * A205650 A205651 A205652

KEYWORD

nonn,base

AUTHOR

Vladimir Shevelev, Jan 30 2012

STATUS

approved

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Last modified June 17 15:28 EDT 2019. Contains 324194 sequences. (Running on oeis4.)