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.

A113315 Niven (or Harshad) numbers A005349 divided by the sum of their digits.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 4, 2, 10, 7, 4, 3, 10, 4, 10, 7, 5, 4, 10, 6, 10, 7, 10, 8, 10, 9, 7, 10, 100, 34, 12, 55, 37, 28, 19, 13, 40, 14, 22, 19, 15, 28, 16, 25, 19, 17, 13, 18, 19, 20, 19, 16, 13, 11, 100, 67, 34, 23, 19, 70, 24, 55, 37, 28, 25, 19, 46, 26, 40, 27, 19, 28, 29
Offset: 1

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Author

Amarnath Murthy, Dec 20 2001

Keywords

Comments

a(n)=10234 is particularly frequent, it is obtained by the following integers: 102340, 133042, 153510, 184212, 204680, 214914, 225148, 235382, 245616, 255850, 266084, 276318, 286552, 327488, 347956, 378658, 388892,.... Carmine Suriano, May 04 2013

Examples

			12 is the 11th term of A005349, hence a(11) = 12/(1+2) = 4.
		

Crossrefs

Cf. A005349 (Niven (or Harshad) numbers: numbers that are divisible by the sum of their digits). Cf. also A066355.

Programs

  • Mathematica
    Select[# / DigitSum[#] & /@ Range[300], IntegerQ] (* Amiram Eldar, May 26 2024 *)
  • PARI
    lista(nn) = {for (i = 1, nn, if (i % sumdigits(i) == 0, print1(i/sumdigits(i), ", ")););} \\ Michel Marcus, Oct 09 2013

Formula

a(n) = A005349(n)/A007953(A005349(n)). - Michel Marcus, Oct 09 2013

Extensions

Corrected, extended and edited by Zak Seidov, Oct 26 2005