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A242806 Integers n such that each of n, n+1, n+2, n+4, n+5, n+6 is the squarefree product of four primes. 3
9743613, 9780589, 22669381, 23209809, 23395137, 26143197, 28042877, 38110029, 43335609, 45127905, 45559613, 47163489, 47944865, 48030229, 48611913, 48762829, 50015301, 50600341, 50742501, 51256541, 52691613 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This is a higher analog to A242804 and A242805.

LINKS

Table of n, a(n) for n=1..21.

EXAMPLE

9743613=3*11*503*587, 9743614=2*59*71*1163, 9743615= 5*7*167*1667, 9743617=13*37*47*431, 9743618=2*17*19*15083, 9743619=3*83*109*359.

PROG

(PARI)

{ default(primelimit, 1000M); i=0; j=0; k=0; l=0; m=0; loc=0; lb=2; ub=9*10^9; o=4; for(n=lb, ub, if(issquarefree(n)&&(o==omega(n)), loc=loc+1; if(1==loc, i=n; ); if(2==loc, if(i+1==n, j=n; ); if(i+1<n, loc=1; i=n; ); ); if(3==loc, if(j+1==n, k=n; ); if(j+1<n, loc=1; i=n; ); ); if(4==loc, if(k+2==n, l=n; ); if(k+2<n, loc=1; i=n; ); ); if(5==loc, if(l+1==n, m=n; ); if(l+1<n, loc=1; i=n; ); ); if(6==loc, if(m+1==n, print1(i, ", "); loc=0; ); if(m+1<n, loc=1; i=n; ); ); ); ); }

CROSSREFS

Cf. A242793 and A242804 (two primes), A242805 (three primes), A242829 (five primes).

Sequence in context: A154573 A058332 A058328 * A016822 A016858 A016978

Adjacent sequences:  A242803 A242804 A242805 * A242807 A242808 A242809

KEYWORD

nonn

AUTHOR

Daniel Constantin Mayer, May 23 2014

STATUS

approved

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Last modified November 19 09:01 EST 2018. Contains 317348 sequences. (Running on oeis4.)