A131470 a(n)=smallest number that gives a product with the sum of digits of n written in base 2 greater than n.

2, 3, 2, 5, 3, 4, 3, 9, 5, 6, 4, 7, 5, 5, 4, 17, 9, 10, 7, 11, 8, 8, 6, 13, 9, 9, 7, 10, 8, 8, 7, 33, 17, 18, 12, 19, 13, 13, 10, 21, 14, 15, 11, 15, 12, 12, 10, 25, 17, 17, 13, 18, 14, 14, 12, 19, 15, 15, 12, 16, 13, 13, 11, 65, 33, 34, 23

Offset

1,1

Links

Table of n, a(n) for n=1..67.

Formula

Let sd2(n) the sum of digits of n written in base 2. Then a(n) =1 + Floor(n/sd2(n)).

Example

9 is written 1001 in base 2, then sd2(9)=2; 4*2<9<5*2; then (c,9)=5

Crossrefs

Sequence in context: A111076 A361624 A162398 * A352708 A255709 A285512

Adjacent sequences: A131467 A131468 A131469 * A131471 A131472 A131473

Keyword

easy,nonn,base

Author

Philippe LALLOUET (philip.lallouet(AT)wanadoo.fr), Jul 27 2007

Status

approved