A228132 First differences of A014311.

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

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