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.

Showing 1-3 of 3 results.

A241097 Largest number <= sqrt(A179204(n)).

Original entry on oeis.org

3, 5, 12, 25, 57, 250, 559, 13238, 1077012, 322656571, 5795765057424, 4027870835232392320, 903791618282646321226570962, 1776210918518890175662636176339649255704, 15280451339626746295314161492940877992251551687044042374879
Offset: 1

Views

Author

J. Lowell, Apr 26 2014

Keywords

Comments

A179204(n+1) is the LCM of A179204(n) and this sequence (n).

Links

Extensions

More terms from Alois P. Heinz, Apr 26 2014

A241083 LCM of n and largest integer <= sqrt(n).

Original entry on oeis.org

1, 2, 3, 4, 10, 6, 14, 8, 9, 30, 33, 12, 39, 42, 15, 16, 68, 36, 76, 20, 84, 44, 92, 24, 25, 130, 135, 140, 145, 30, 155, 160, 165, 170, 35, 36, 222, 114, 78, 120, 246, 42, 258, 132, 90, 138, 282, 48, 49, 350, 357, 364, 371, 378, 385, 56, 399, 406, 413, 420
Offset: 1

Views

Author

J. Lowell, Apr 15 2014

Keywords

Comments

a(n) = n iff n is in A006446. - Ivan Neretin, Apr 27 2017

Examples

			a(18) cannot be 18 because 18 is not a multiple of 4, the largest integer <= sqrt(18).

Links

Crossrefs

A179204 is a sequence that can be defined in terms of this sequence.
Cf. A000196.

Programs

Formula

a(n) = lcm(n, floor(sqrt(n))) = lcm(n, A000196(n)). - Wesley Ivan Hurt, Apr 15 2014

Extensions

Extended by Wesley Ivan Hurt, Apr 15 2014

A241974 a(n) is the limit of the sequence given by A241083^[i](n), where f^[i] means iterate f i times, or 0 if the sequence diverges.

Original entry on oeis.org

1, 2, 3, 4, 30, 6, 42, 8, 9, 30
Offset: 1

Views

Author

J. Lowell, May 03 2014

Keywords

Comments

Either a(11) = 0 or a(11) > 10^(1310).

Examples

			a(5) = 30 because A241083(5) = 10, A241083(10) = 30, and A241083(30) = 30.

Crossrefs

Cf. A241083, A179204.

Programs

  • Mathematica
    a[n_] := FixedPoint[LCM[#, Floor[Sqrt[#]]] &, n]; Array[a, 10] (* Amiram Eldar, Jul 26 2025 *)
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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