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A264046 Numbers n such that n and n+6 are consecutive semiprimes. 2
15, 123, 365, 371, 505, 545, 573, 591, 649, 707, 807, 843, 943, 1067, 1159, 1247, 1357, 1405, 1529, 1555, 1633, 1739, 1745, 1829, 1843, 1897, 1909, 1985, 2149, 2159, 2209, 2285, 2329, 2353, 2363, 2407, 2413, 2463, 2501, 2643, 2773, 2779 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Note that a(1)=15=A131109(k=6).

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

15=A001358(6) and 21=A001358(7).

PROG

(PARI) is(n)=if(bigomega(n)!=2 || bigomega(n+6)!=2, return(0)); for(i=1, 5, if(bigomega(n+i)==2, return(0))); 1 \\ Charles R Greathouse IV, Nov 02 2015

CROSSREFS

Cf. A001358, A065516, A123375, A131109, A136196, A264043, A264044, A264045.

Sequence in context: A264377 A038743 A181377 * A027839 A034271 A171220

Adjacent sequences:  A264043 A264044 A264045 * A264047 A264048 A264049

KEYWORD

nonn

AUTHOR

Zak Seidov, Nov 02 2015

STATUS

approved

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Last modified November 14 04:56 EST 2019. Contains 329110 sequences. (Running on oeis4.)