A143262 - OEIS

A143262

a(n) = the number of times the binary representation of the number of divisors of n occurs in the binary representation of n.

1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 0, 2, 1, 1, 0, 1, 0, 1, 1, 1, 1, 2, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 2, 1, 0, 1, 1, 0, 1, 1, 1, 1, 2, 0, 0, 0, 0, 1, 2, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 2, 0, 1, 1, 0

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

OFFSET

1,37

LINKS

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

EXAMPLE

37 has 2 divisors. 37 in binary is 100101. 2 in binary is 10. 10 occurs in two places in 100101: (10)0(10)1. So a(37) = 2.

MATHEMATICA

Table[SequenceCount[IntegerDigits[n, 2], IntegerDigits[DivisorSigma[0, n], 2]], {n, 110}] (* The program uses the SequenceCount function from Mathematica version 10.1 *) (* Harvey P. Dale, Apr 02 2015 *)

CROSSREFS

Cf. A143263, A143264.

Sequence in context: A378622 A279126 A210679 * A379590 A382630 A035180

Adjacent sequences: A143259 A143260 A143261 * A143263 A143264 A143265

KEYWORD

base,nonn

AUTHOR

Leroy Quet, Aug 03 2008

EXTENSIONS

Extended by Ray Chandler, Nov 09 2008

STATUS

approved