A082811 Smallest multiple of n beginning with 2.

2, 2, 21, 20, 20, 24, 21, 24, 27, 20, 22, 24, 26, 28, 210, 208, 204, 216, 209, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 210, 217, 224, 231, 204, 210, 216, 222, 228, 234, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 200, 204, 208, 212, 216, 220

Offset

1,1

Comments

a(n) is in {n, 2n, 3n, 4n, 5n, 6n, 7n, 11n, 12n, 13n, 14n}. [Charles R Greathouse IV, Mar 06 2011]

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Mathematica

f[n_] := Block[{m = n}, While[ First@ IntegerDigits@ m != 2, m += n]; m]; Array[f, 55] (* Robert G. Wilson v *)

Prog

(PARI) a(n)=forstep(k=n, 14*n, n, if(Vec(Str(k))[1]=="2", return(k))) \\ Charles R Greathouse IV, Mar 06 2011
(Sage) def A082811(n): return next(k for k in PositiveIntegers() if (n*k).digits()[-1] == 2) # D. S. McNeil, Mar 07 2011
(Haskell)
a082811 n = until ((== 2) . a000030) (+ n) n
-- Reinhard Zumkeller, Mar 27 2012

Crossrefs

Cf. A082784, A054850, A082786, A082787, A082788, A082789, A082791.

Cf. A000030.

Sequence in context: A184717 A134046 A081687 * A014353 A353101 A079032

Adjacent sequences: A082808 A082809 A082810 * A082812 A082813 A082814

Keyword

base,easy,nonn

Author

Amarnath Murthy, Apr 19 2003

Status

approved