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A023688 Numbers with exactly 6 ones in binary expansion. 14
63, 95, 111, 119, 123, 125, 126, 159, 175, 183, 187, 189, 190, 207, 215, 219, 221, 222, 231, 235, 237, 238, 243, 245, 246, 249, 250, 252, 287, 303, 311, 315, 317, 318, 335, 343, 347, 349, 350, 359, 363, 365, 366, 371, 373 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Appears to give all n such that 8^5 is the highest power of 2 dividing A005148 (n). General conjecture: numbers k such that 8^a is the highest power of 2 dividing A005148 (k) is the same sequence as numbers k such that k has exactly (a+1) 1's in his binary representation. - Benoit Cloitre, Jun 22 2002

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

FORMULA

a(n+1) = A057168(a(n)). - M. F. Hasler, Aug 27 2014

MATHEMATICA

Select[ Range[ 63, 380 ], (Count[ IntegerDigits[ #, 2 ], 1 ]==6)& ]

PROG

(PARI) is_A023688(n)=hammingweight(n)==6 \\ M. F. Hasler, Aug 27 2014

(PARI) print1(t=2^6-1); for(i=2, 50, print1(", "t=A057168(t))) \\ M. F. Hasler, Aug 27 2014

CROSSREFS

Cf. A000079, A018900, A014311, A014312, A014313, A023688, A023689, A023690, A023691 (Hamming weight = 1, 2, ..., 9).

Sequence in context: A062375 A253021 A039480 * A118157 A257897 A261108

Adjacent sequences:  A023685 A023686 A023687 * A023689 A023690 A023691

KEYWORD

nonn,base,easy

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified June 25 22:15 EDT 2017. Contains 288730 sequences.