cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A061219 a(n) is the largest number which can be formed with no zeros, using least number of digits and having digit sum = n.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 91, 92, 93, 94, 95, 96, 97, 98, 99, 991, 992, 993, 994, 995, 996, 997, 998, 999, 9991, 9992, 9993, 9994, 9995, 9996, 9997, 9998, 9999, 99991, 99992, 99993, 99994, 99995, 99996, 99997, 99998, 99999, 999991, 999992, 999993, 999994
Offset: 1

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Author

Amarnath Murthy, Apr 22 2001

Keywords

Comments

a(n) is the digit reversal of terms of A051885 giving such smallest numbers.

Examples

			a(22) = 994, digit sum = 22.
a(100) = 999999999991.
		

Crossrefs

Cf. A051885.

Programs

  • Mathematica
    dsn[n_]:=Module[{d=Quotient[n,9]},FromDigits[PadLeft[{n-9d},d,9]]]; If[Divisible[#,10],#/10,#]&/@Array[dsn,50,10] (* Harvey P. Dale, Dec 08 2013 *)
  • Python
    def a(n): return int("9"*(n//9)+str(n%9)*(n%9>0))
    print([a(n) for n in range(1, 50)]) # Michael S. Branicky, Aug 16 2023

Extensions

More terms from Harvey P. Dale, Dec 08 2013
Offset corrected by Michael S. Branicky, Aug 16 2023