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.

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A034174 a(n) is minimal such that prime factorizations of a(n)-n+1, ..., a(n) have same exponents.

Original entry on oeis.org

1, 3, 35, 19943, 204327, 380480350, 440738966079
Offset: 1

Views

Author

Dean Hickerson, Oct 01 1998

Keywords

Comments

The final terms of the arithmetic progressions defined in A083785. - N. J. A. Sloane, Oct 18 2007
a(8) > 10^13. - Donovan Johnson, Oct 20 2009. [See Reble link for an upper limit.]
The main entry is A034173, which should be updated whenever something relevant is added here. - M. F. Hasler, Oct 28 2012

Examples

			a(4)=19943 because 19940, ..., 19943 all have the form p^2 q r.
		

Crossrefs

Diagonal of A083785. Cf. A034173, A083785, A083787. See A034173 for more.

Programs

  • PARI
    A034174(n)={my(f); for(k=n, oo, f=0; for(i=0, n-1, f==(f=vecsort(factor(k-i)[, 2])) || !i || [k+=n-i-1; next(2)]); return(k))} \\ For illustrative purpose; not useful for n>=6. - M. F. Hasler, Oct 28 2012

Formula

a(n) = A034173(n) + n - 1. - Max Alekseyev, Nov 10 2009

Extensions

a(7) from Donovan Johnson, Oct 20 2009

A083785 Triangle read by rows in which the n-th row gives the smallest set of n consecutive numbers with the same prime signatures.

Original entry on oeis.org

1, 2, 3, 33, 34, 35, 19940, 19941, 19942, 19943, 204323, 204324, 204325, 204326, 204327, 380480345, 380480346, 380480347, 380480348, 380480349, 380480350, 440738966073, 440738966074, 440738966075, 440738966076, 440738966077, 440738966078, 440738966079
Offset: 1

Views

Author

Amarnath Murthy, May 07 2003

Keywords

Examples

			       1
       2      3
      33     34     35
   19940  19941  19942  19943
  204323 204324 204325 204326 204327
  ...
		

Crossrefs

The first column is given by A034173, the final terms by A034174.

Extensions

7th row added using A034173 by Michel Marcus, Dec 13 2015
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