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.

A133689 a(n) = smallest integer that is > n and is a multiple of every proper divisor of n.

Original entry on oeis.org

3, 4, 6, 6, 12, 8, 12, 12, 20, 12, 24, 14, 28, 30, 24, 18, 36, 20, 40, 42, 44, 24, 48, 30, 52, 36, 56, 30, 60, 32, 48, 66, 68, 70, 72, 38, 76, 78, 80, 42, 84, 44, 88, 90, 92, 48, 96, 56, 100, 102, 104, 54, 108, 110, 112, 114, 116, 60
Offset: 2

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Author

Leroy Quet, Dec 31 2007

Keywords

Comments

a(n) = A048671(n) + n.

Examples

			The proper divisors of 16 are 1,2,4,8. a(16)=24 is the smallest integer which is both > 16 and is a multiple of 1, of 2, of 4 and of 8.
		

Crossrefs

Cf. A048671.

Programs

  • Mathematica
    a = {}; For[n = 2, n < 60, n++, i = n + 1; While[Length[Union[Mod[i, Complement[Divisors[n], {n}]]]] > 1, i++ ]; AppendTo[a, i]]; a (* Stefan Steinerberger, Aug 30 2008 *)

Extensions

More terms from Stefan Steinerberger, Aug 30 2008