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A226899 Numbers n for which Delta(m) < Delta(n) for all m < n, where Delta is Hooley's Delta function A226898. 4
1, 2, 12, 24, 120, 180, 360, 720, 1260, 2520, 5040, 10080, 15120, 27720, 30240, 50400, 55440, 65520, 83160, 110880, 166320, 221760, 277200, 332640, 360360, 554400, 665280, 720720, 1441440, 2162160, 3603600, 4324320, 7207200, 8648640, 10810800, 14414400, 21621600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Not a subsequence of A025487: a(18) = 65520 = 2^4 * 3^2 * 5 * 7 * 13, a(46) = 136936800 = 2^5 * 3^2 * 5^2 * 7 * 11 * 13 * 19, and a(50) = 273873600 = 2^6 * 3^2 * 5^2 * 7 * 11 * 13 * 19. - Charles R Greathouse IV, Mar 12 2018

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..64

C. Hooley, On a new technique and its applications to the theory of numbers, Proc. London Math. Soc. 3 38:1 (1979), pp. 115-151.

PROG

(PARI) Delta(n)=my(d=divisors(n), r, t); for(i=1, #d\2, t=setsearch(d, d[i]*exp(1)\1, 1); t=if(t, t-i, setsearch(d, d[i]*exp(1)\1)+1-i); if(t>r, r=t)); r

r=0; for(n=1, 1e9, t=Delta(n); if(t>r, r=t; print1(n", ")))

CROSSREFS

Cf. A226898, A226900, A002182.

Sequence in context: A224923 A247086 A121119 * A052565 A176710 A141900

Adjacent sequences:  A226896 A226897 A226898 * A226900 A226901 A226902

KEYWORD

nonn

AUTHOR

Charles R Greathouse IV, Jun 21 2013

STATUS

approved

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Last modified May 19 14:36 EDT 2019. Contains 323395 sequences. (Running on oeis4.)