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A070313 a(n) = 2^n - (2*n+1). 7
0, -1, -1, 1, 7, 21, 51, 113, 239, 493, 1003, 2025, 4071, 8165, 16355, 32737, 65503, 131037, 262107, 524249, 1048535, 2097109, 4194259, 8388561, 16777167, 33554381, 67108811, 134217673, 268435399, 536870853, 1073741763, 2147483585 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Binomial transform of (-1)^n!+!n. - Paul Barry, May 13 2004

This appears as the exponent in Krotov, who writes on p. 2: "in general, two extended Hamming codes can intersect in 2^(2^m - 2m - 1) elements." - Jonathan Vos Post, Jan 13 2013

Primes appear at positions n = 4, 7, 8, 28, 32, 81, 669, 1108, ... . - R. J. Mathar, Jan 22 2013

LINKS

Table of n, a(n) for n=0..31.

Denis Krotov, A partition of the hypercube into cosets of maximally nonparallel Hamming codes, arXiv:1210.0010v1 [cs.IT], Sep 28, 2012.

D. P. Roselle, Permutations by number of rises and successions, Proc. Amer. Math. Soc., 19 (1968), 8-16.

D. P. Roselle, Permutations by number of rises and successions, Proc. Amer. Math. Soc., 19 (1968), 8-16. [Annotated scanned copy]

Index entries for linear recurrences with constant coefficients, signature (4,-5,2).

FORMULA

E.g.f.: (exp(x))^2 - exp(x) - 2xexp(x). - Paul Barry, May 13 2004

From Colin Barker, Mar 21 2012: (Start)

a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3).

G.f.: -x*(1-3*x)/((1-x)^2*(1-2*x)). (End)

MATHEMATICA

lst={}; s=-1; Do[s+=s+n; AppendTo[lst, s], {n, 1, 5!, 2}]; lst (* Vladimir Joseph Stephan Orlovsky, Oct 18 2008 *)

PROG

(Maxima) makelist(2^n - (2*n+1), n, 0, 20); /* Martin Ettl, Jan 25 2013 */

(PARI) a(n)=2^n-(2*n+1) \\ Charles R Greathouse IV, Oct 07 2015

CROSSREFS

Second diagonal of A046739.

Sequence in context: A146613 A083012 A233329 * A146733 A146709 A146400

Adjacent sequences:  A070310 A070311 A070312 * A070314 A070315 A070316

KEYWORD

sign,easy

AUTHOR

N. J. A. Sloane, May 16 2002

STATUS

approved

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Last modified October 22 16:15 EDT 2021. Contains 348174 sequences. (Running on oeis4.)