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A209248 a(n) = 2^(2^n - 2*n - 1). 0

%I #25 Feb 11 2020 09:57:42

%S 2,128,2097152,2251799813685248,10384593717069655257060992658440192,

%T 883423532389192164791648750371459257913741948437809479060803100646309888

%N a(n) = 2^(2^n - 2*n - 1).

%C a(n) = 2^A070313(n). Krotov on p. 2: "in general, two extended Hamming codes can intersect in 2^(2^m - 2m - 1) elements."

%H Denis Krotov, <a href="http://arxiv.org/abs/1210.0010">A partition of the hypercube into cosets of maximally nonparallel Hamming codes</a>, arXiv:1210.0010v1 [cs.IT], 2012-2016.

%H <a href="/index/Di#divseq">Index to divisibility sequences</a>

%e a(5) = 2^(2^5 - 2*5 - 1) = 2^21 = 2097152.

%t Table[2^(2^n - 2n - 1), {n, 3, 15}] (* _Alonso del Arte_, Jan 13 2013 *)

%o (PARI) 1<<(2^n-2*n-1) \\ _Charles R Greathouse IV_, Jan 24 2013

%o (Maxima) makelist(floor(2^(2^n-2*n-1)),n,3,8); /* _Martin Ettl_, Jan 25 2013 */

%Y Cf. A070313.

%K nonn,easy

%O 3,1

%A _Jonathan Vos Post_, Jan 13 2013

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Last modified April 25 16:45 EDT 2024. Contains 371989 sequences. (Running on oeis4.)