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
Examples
a(3) = 123264 = 321*384.
Links
- Robert Gerbicz, May 09 2008, Table of n, a(n) for n = 1..17
Crossrefs
Cf. A078207.
Programs
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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
Extensions
More terms from Robert Gerbicz, May 09 2008