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A047473 Numbers that are congruent to {2, 3} mod 8. 1
2, 3, 10, 11, 18, 19, 26, 27, 34, 35, 42, 43, 50, 51, 58, 59, 66, 67, 74, 75, 82, 83, 90, 91, 98, 99, 106, 107, 114, 115, 122, 123, 130, 131, 138, 139, 146, 147, 154, 155, 162, 163, 170, 171, 178, 179, 186, 187, 194, 195, 202, 203, 210, 211, 218, 219, 226, 227, 234 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers k such that k and k+2 have the same digital binary sum. - Benoit Cloitre, Dec 01 2002

Also, numbers k such that k*(3*k + 1)/8 + 1/4 is a nonnegative integer. - Bruno Berselli, Feb 14 2017

LINKS

Table of n, a(n) for n=1..59.

Index entries for linear recurrences with constant coefficients, signature (1,1,-1).

FORMULA

a(n) = 8*n - a(n-1) - 11 for n>1, a(1)=2. - Vincenzo Librandi, Aug 06 2010

From R. J. Mathar, Oct 08 2011: (Start)

a(n) = 4*n - 7/2 - 3*(-1)^n/2.

G.f.: x*(2 + x + 5*x^2)/((1 + x)*(1 - x)^2). (End)

a(1)=2, a(2)=3, a(3)=10; for n>3, a(n) = a(n-1) + a(n-2) - a(n-3). - Harvey P. Dale, Sep 28 2012

MATHEMATICA

Flatten[# + {2, 3} &/@ (8 Range[0, 30])] (* or *) LinearRecurrence[{1, 1, -1}, {2, 3, 10}, 60] (* Harvey P. Dale, Sep 28 2012 *)

CROSSREFS

Sequence in context: A081706 A032804 A248407 * A270474 A008509 A281366

Adjacent sequences:  A047470 A047471 A047472 * A047474 A047475 A047476

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vincenzo Librandi, Aug 06 2010

STATUS

approved

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Last modified December 16 12:37 EST 2018. Contains 318160 sequences. (Running on oeis4.)