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A060355 Numbers n such that n and n+1 are a pair of consecutive powerful numbers. +0
5
8, 288, 675, 9800, 12167, 235224, 332928, 465124, 1825200, 11309768, 384199200, 592192224, 4931691075, 5425069447, 13051463048, 221322261600, 443365544448, 865363202000, 8192480787000, 11968683934831, 13325427460800 (list; graph; listen)
OFFSET

1,1

COMMENT

"Erdos conjectured in 1975 that there do not exist three consecutive powerful integers." - Guy

1825200 belongs to the sequence because 1825200=2.2.2.2.3.3.3.5.5.13.13, 1825201=7.7.193.193=1351^2 and both are powerful numbers. - Labos E. (labos(AT)ana.sote.hu), May 03 2001.

See Guy for Erdos' conjecture and statement that this sequence is infinite. - Jud McCranie (JudMcCr(AT)BellSouth.net), Oct 13 2002

It is easy to see that this sequence is infinite: if n is in the sequence, so is 4n(n+1). [From Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Sep 16 2009]

REFERENCES

J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 288, pp 74, Ellipses, Paris 2008.

R. K. Guy, Unsolved Problems in Number Theory, B16

LINKS

C. K. Caldwell, Powerful Numbers

Eric Weisstein's World of Mathematics, Powerful numbers

CROSSREFS

Cf. A001694, A060859.

Sequence in context: A079929 A136364 A089670 this_sequence A060859 A054607 A132592

Adjacent sequences: A060352 A060353 A060354 this_sequence A060356 A060357 A060358

KEYWORD

nonn

AUTHOR

Jason Earls (zevi_35711(AT)yahoo.com), Apr 01 2001

EXTENSIONS

Corrected and extended by Jud McCranie (j.mccranie(AT)comcast.net), Jul 08 2001

More terms from Jud McCranie (JudMcCr(AT)BellSouth.net), Oct 13 2002

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Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


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