The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A124167 a(n) = 10*(10^n-1). 1
 0, 90, 990, 9990, 99990, 999990, 9999990, 99999990, 999999990, 9999999990, 99999999990, 999999999990, 9999999999990, 99999999999990, 999999999999990, 9999999999999990, 99999999999999990, 999999999999999990 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS a(n - 1) is the maximum difference between an n-digit number (written in base 10, nonzero leading digit) and the product of its digits. For n>1, it is also a number meeting that bound. See A070565. - Devin Akman, Apr 17 2019 LINKS Michael De Vlieger, Table of n, a(n) for n = 0..999 Index entries for linear recurrences with constant coefficients, signature (11,-10). FORMULA a(n) = 10*A002283(n). From G. C. Greubel, Jun 30 2019: (Start) a(n) = 90*A002275(n). a(n) = 11*a(n-1) - 10*a(n-2). G.f.: 10*(1/(1-10*x) - 1/(1-x)). E.g.f.: 10*(exp(10*x) - exp(x)). (End) MAPLE a:=n->sum (10^(n-j+2)-10^(n-j+1), j=0..n): seq(a(n), n=0..20); MATHEMATICA Array[10 (10^# - 1) &, 20, 0] (* Michael De Vlieger, Apr 21 2019 *) PROG (PARI) vector(20, n, n--; 10*(10^n -1)) \\ G. C. Greubel, Jun 30 2019 (MAGMA) [10*(10^n -1): n in [0..20]]; // G. C. Greubel, Jun 30 2019 (Sage) [10*(10^n -1) for n in (0..20)] # G. C. Greubel, Jun 30 2019 (GAP) List([0..20], n-> 10*(10^n -1)) # G. C. Greubel, Jun 30 2019 CROSSREFS Partial sums give 10*A099676. Cf. A002283, A002275, A070565. Sequence in context: A101243 A173483 A202960 * A223364 A048548 A013427 Adjacent sequences:  A124164 A124165 A124166 * A124168 A124169 A124170 KEYWORD easy,nonn AUTHOR Zerinvary Lajos, Dec 02 2006 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 25 12:23 EDT 2020. Contains 337343 sequences. (Running on oeis4.)