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A075029 Smallest initial number k of n consecutive numbers satisfying numdiv(k) > numdiv(k+1) > ... > numdiv(k+n-1). 4
1, 4, 45, 80, 28974, 28974, 8489103, 80314575, 5196065775, 77506573550, 166622964149389, 489289301397948 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(11) > 10^12. - Donovan Johnson, Oct 13 2009

a(11) > 10^13. - Giovanni Resta, Jul 25 2013

a(13) > 2.64*10^15. - Jud McCranie, Mar 27 2019

REFERENCES

J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 45, p. 17, Ellipses, Paris 2008.

LINKS

Table of n, a(n) for n=1..12.

EXAMPLE

a(4) = 80, as tau(80) = 10 > tau(81) = 5 > tau(82) = 4 > tau(83) = 2.

PROG

(PARI) n=2; for(k=1, 100, while(1, m=n; s=1; while(numdiv(m)<numdiv(m-1), s=s+1; m=m+1); if(s>=k, print1(n-1, ", "); break); n=n+1))

CROSSREFS

Cf. A075028, A075031.

Sequence in context: A024254 A167781 A173327 * A070225 A132998 A120075

Adjacent sequences:  A075026 A075027 A075028 * A075030 A075031 A075032

KEYWORD

nonn,more

AUTHOR

Amarnath Murthy, Sep 02 2002

EXTENSIONS

Edited by Ralf Stephan, Mar 21 2003

Definition corrected by Leroy Quet, Feb 23 2008

2 more terms from Lekraj Beedassy, Jul 13 2008

a(9)-a(10) from Donovan Johnson, Oct 13 2009

a(11)-a(12) from Jud McCranie, Mar 27 2019

STATUS

approved

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Last modified May 31 13:01 EDT 2020. Contains 334748 sequences. (Running on oeis4.)