A226899 Numbers n for which Delta(m) < Delta(n) for all m < n, where Delta is Hooley's Delta function A226898.

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

Offset: 1

Author

Charles R Greathouse IV, Jun 21 2013

Keywords

• nonn

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.

Crossrefs

Cf. A226898, A226900, A002182.

Programs

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", ")))