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A232710 Binary numbers (written in decimal) such that the sum of digits mod 2 equals the product of digits mod 2. 0
0, 1, 5, 6, 7, 9, 10, 12, 17, 18, 20, 23, 24, 27, 29, 30, 31, 33, 34, 36, 39, 40, 43, 45, 46, 48, 51, 53, 54, 57, 58, 60, 65, 66, 68, 71, 72, 75, 77, 78, 80, 83, 85, 86, 89, 90, 92, 95, 96, 99, 101, 102, 105, 106, 108, 111, 113, 114, 116, 119, 120, 123, 125 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..62.

Index entries for sequences related to binary expansion of n

FORMULA

A083420 UNION (A001969 \ {3}). - Ralf Stephan, Nov 30 2013

EXAMPLE

23 is in the sequence because 23 in binary is 10111. The sum of digits is 4 == 0 mod 2 and the products of digits is 0 == 0 mod 2.

PROG

(JavaScript)

for (i=0; i<1000; i++) {

s=i.toString(2).split("");

sl=s.length;

c=0; d=1;

for (j=0; j<sl; j++) {c+=s[j]*1; d*=s[j]; }

c%=2; d%=2;

if (c==d) document.write(i+", ");

}

(PARI) is(n)=b=binary(n); sum(i=1, #b, b[i])%2==prod(i=1, #b, b[i])%2 \\ Ralf Stephan, Nov 30 2013

CROSSREFS

Sequence in context: A246782 A089192 A279195 * A132829 A180061 A196029

Adjacent sequences:  A232707 A232708 A232709 * A232711 A232712 A232713

KEYWORD

nonn,base

AUTHOR

Jon Perry, Nov 28 2013

STATUS

approved

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Last modified October 23 17:32 EDT 2019. Contains 328373 sequences. (Running on oeis4.)