A115454 - OEIS

A115454

Composite positive integers written in base 2.

100, 110, 1000, 1001, 1010, 1100, 1110, 1111, 10000, 10010, 10100, 10101, 10110, 11000, 11001, 11010, 11011, 11100, 11110, 100000, 100001, 100010, 100011, 100100, 100110, 100111, 101000, 101010, 101100, 101101, 101110, 110000, 110001

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

If n is in the sequence then so is 10 * n. - David A. Corneth, Aug 17 2018

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A007088(A002808(n)).

MAPLE

map(convert, remove(isprime, [$4..200]), binary); # Robert Israel, Aug 17 2018

MATHEMATICA

For[n = 2, n < 50, n++, If[Not[PrimeQ[n]], Print[BaseForm[n, 2]]]] (* Stefan Steinerberger, Jan 24 2006 *)

PROG

(PARI) lista(nn) = forcomposite(n=1, nn, print1(fromdigits(binary(n), 10), ", ")); \\ Michel Marcus, Aug 17 2018

CROSSREFS

Cf. A002808, A007088, A004676.

Sequence in context: A348139 A162530 A204590 * A122466 A066511 A281193

Adjacent sequences: A115451 A115452 A115453 * A115455 A115456 A115457

KEYWORD

base,nonn

AUTHOR

Leroy Quet, Jan 22 2006

EXTENSIONS

More terms from Stefan Steinerberger, Jan 24 2006

STATUS

approved