The On-Line Encyclopedia of Integer Sequences (OEIS)

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Revision History for A355433

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A355433

Numbers k such that k is sqrt(k)-smooth and k+1 is sqrt(k+1)-smooth.
(history; published version)

#10 by Joerg Arndt at Mon Jul 04 04:38:40 EDT 2022

STATUS

reviewed

approved

#9 by Michel Marcus at Mon Jul 04 03:05:59 EDT 2022

STATUS

proposed

reviewed

#8 by Amiram Eldar at Mon Jul 04 02:39:18 EDT 2022

STATUS

editing

proposed

#7 by Amiram Eldar at Mon Jul 04 02:14:59 EDT 2022

LINKS

Amiram Eldar, <a href="/A355433/b355433.txt">Table of n, a(n) for n = 1..10000</a>

STATUS

approved

editing

#6 by Peter Luschny at Sat Jul 02 09:28:29 EDT 2022

STATUS

reviewed

approved

#5 by Joerg Arndt at Sat Jul 02 09:07:41 EDT 2022

STATUS

proposed

reviewed

#4 by Amiram Eldar at Sat Jul 02 03:38:41 EDT 2022

STATUS

editing

proposed

#3 by Amiram Eldar at Sat Jul 02 03:07:10 EDT 2022

NAME

allocated for Amiram EldarNumbers k such that k is sqrt(k)-smooth and k+1 is sqrt(k+1)-smooth.

DATA

8, 24, 48, 49, 63, 80, 120, 125, 168, 175, 195, 224, 242, 288, 324, 350, 351, 360, 363, 374, 384, 399, 440, 441, 455, 475, 494, 512, 528, 539, 560, 575, 594, 624, 675, 714, 728, 735, 759, 832, 840, 874, 896, 935, 960, 968, 1000, 1014, 1023, 1044, 1053, 1088, 1104

OFFSET

1,1

COMMENTS

Numbers k such that k and k+1 are both in A048098.

This sequence is infinite: if p is an odd prime then p^2-1 is a term.

EXAMPLE

8 is a term since 8 is sqrt(8)-smooth (2^2 <= 8) and 9 is sqrt(9)-smooth (3^2 <= 9).

MATHEMATICA

smQ[n_] := FactorInteger[n][[-1, 1]]^2 <= n; Select[Range[1000], smQ[#] && smQ[# + 1] &]

CROSSREFS

Cf. A048098, A355434.

Subsequences: A084920 \ {3}, A060355, A348119.

KEYWORD

allocated

nonn

AUTHOR

Amiram Eldar, Jul 02 2022

STATUS

approved

editing

#2 by Amiram Eldar at Sat Jul 02 03:04:24 EDT 2022

KEYWORD

allocating

allocated

#1 by Amiram Eldar at Sat Jul 02 03:04:24 EDT 2022

NAME

allocated for Amiram Eldar

KEYWORD

allocating

STATUS

approved