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A228132 First differences of A014311. 1
4, 2, 1, 5, 2, 1, 3, 1, 2, 7, 2, 1, 3, 1, 2, 5, 1, 2, 4, 11, 2, 1, 3, 1, 2, 5, 1, 2, 4, 9, 1, 2, 4, 8, 19, 2, 1, 3, 1, 2, 5, 1, 2, 4, 9, 1, 2, 4, 8, 17, 1, 2, 4, 8, 16, 35, 2, 1, 3, 1, 2, 5, 1, 2, 4, 9, 1, 2, 4, 8, 17, 1, 2, 4, 8, 16, 33, 1, 2, 4, 8, 16, 32 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The records are: 4, 5, 7, 11, 19, 35, 67, ... and they occur at these indices of A014311: 11, 19, 35, 67, ... (for both, see A062709). - Michel Marcus, Jun 11 2015

The record (maximum) among the first 1000 terms is 65539. - Harvey P. Dale, May 29 2018

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Differences[Select[Range[500], DigitCount[#, 2, 1]==3&]] (* Harvey P. Dale, May 29 2018 *)

PROG

(JavaScript)

oo=0;

for (i=1; i<500; i++) {

s=i.toString(2);

o=0;

for (j=0; j<s.length; j++) if (s.charAt(j)==1) o++;

if (o==3) {document.write(i-oo+", "); oo=i; }

}

(PARI) lista(nn) = {my(last = 0); for (n=1, nn, if (hammingweight(n)==3, if (last, print1(n-last, ", ")); last = n; ); ); } \\ Michel Marcus, Jun 10 2015

CROSSREFS

Cf. A062709 (2^n+3), A014311 (numbers with exactly 3 ones in binary expansion).

Cf. A145057.

Sequence in context: A210937 A016506 A346995 * A146321 A133455 A122606

Adjacent sequences: A228129 A228130 A228131 * A228133 A228134 A228135

KEYWORD

nonn,base

AUTHOR

Jon Perry, Nov 02 2013

STATUS

approved

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Last modified February 4 13:47 EST 2023. Contains 360055 sequences. (Running on oeis4.)