A064683 Let n(s) be the number formed from n by inserting s 0's between each digit, e.g. 123(2) is 1002003; sequence gives numbers n such that n(s) is divisible by n for some s>0.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 26, 27, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 73, 74, 77, 78, 79, 80, 81, 82, 83, 84, 85

Offset

1,2

Comments

If n=d(v)*10^v + d(v-1)*10^(v-1) .. + d(1)*10+d(0) then n(s) = d(v)*10^(v*(1+s))+d(v-1)*10^(v-1)*(1+s)+ .. + d(1)*10^(1+s)+d(0); e.g. 123(2) is 1*10^(2*3)+ 2*10^(1*3)+3*10^(0*3) = 1002003.

Links

Table of n, a(n) for n=1..72.

Example

a(12) = 13 because 13(6) = 10,000,003 which is divisible by 13

Crossrefs

Cf. A064695, A064696, A064697, A064698.

Sequence in context: A084176 A059389 A191328 * A317468 A329481 A261355

Adjacent sequences: A064680 A064681 A064682 * A064684 A064685 A064686

Keyword

base,nonn

Author

Jonathan Ayres (jonathan.ayres(AT)btinternet.com), Oct 10 2001

Status

approved