A100761 Beginning with 1, the smallest positive number which when appended to the reverse concatenation of all previous terms gives a multiple of n.

1, 2, 3, 2, 5, 2, 3, 6, 3, 10, 4, 16, 22, 6, 5, 6, 2, 10, 15, 20, 25, 30, 12, 6, 25, 2, 9, 2, 2, 20, 34, 28, 16, 22, 30, 44, 17, 46, 48, 20, 47, 44, 34, 32, 45, 24, 35, 28, 38, 50, 47, 24, 1, 50, 20, 36, 1, 34, 51, 20, 35, 34, 66, 28, 60, 38, 16, 32, 33, 50, 3, 28, 66, 66, 75, 12, 4, 26

Offset

1,2

Links

Table of n, a(n) for n=1..78.

Example

a(2) = 2, 2 divides 12, a(3) = 3, 213 is a multiple of 3, a(4) = 2, 3212 is a multiple of 4.
a(11) = 4, 103632523214 == 0 (mod 11) where 103632523214 is 10363252321 followed by a 4.

Mathematica

a[1] = 1; a[n_] := a[n] = Block[{k = 1, t = Flatten[ Table[ IntegerDigits[ a[n - i]], {i, n - 1}]]}, While[ Mod[ FromDigits[ Join[t, IntegerDigits[k]]], n] != 0, k++ ]; k]; Table[ a[n], {n, 78}] (* Robert G. Wilson v, Nov 26 2004 *)

Crossrefs

Sequence in context: A087986 A129088 A086418 * A336964 A027748 A361650

Adjacent sequences: A100758 A100759 A100760 * A100762 A100763 A100764

Keyword

base,nonn

Author

Amarnath Murthy, Nov 25 2004

Extensions

More terms from Robert G. Wilson v, Nov 26 2004

Status

approved