A078206 Smallest multiple of the concatenation of n down to 1 that begins with the concatenation of 1 up to n.

1, 126, 123264, 12340776, 1234553367, 123456631959, 12345677303863, 1234567810050426, 123456789137345679, 1234567891008671105551, 1234567891011073225118178, 123456789101112073716778055751

Offset

1,2

Links

Robert Gerbicz, May 09 2008, Table of n, a(n) for n = 1..17

Example

a(3) = 123264 = 321*384.

Prog

(PARI) A=B=0; e=f=0; U=1; for(n=1, 17, if(n==U, U*=10; f++); A=U*A+n; B+=n*10^e; e+=f; T=1; C=A; while((-C)%B>=T, T*=10; C*=10); print1(C+(-C)%B", ")) \\ Robert Gerbicz, May 09 2008

Crossrefs

Cf. A078207.

Sequence in context: A178189 A365026 A294852 * A025037 A281478 A212927

Adjacent sequences: A078203 A078204 A078205 * A078207 A078208 A078209

Keyword

base,nonn

Author

Amarnath Murthy, Nov 22 2002

Extensions

More terms from Robert Gerbicz, May 09 2008

Status

approved