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A240593
The smaller of a pair of consecutive composite squarefree numbers (A120944) without any prime number between them.
1
14, 21, 33, 34, 38, 55, 57, 62, 65, 69, 74, 77, 85, 86, 91, 93, 94, 105, 110, 114, 115, 118, 119, 122, 129, 133, 141, 142, 143, 145, 154, 158, 159, 165, 174, 177, 182, 183, 185, 186, 187, 194, 201, 202, 203, 205, 206, 209, 213, 214, 215, 217, 218, 219, 221, 230, 235, 237, 246, 247, 253, 254, 258, 259, 265, 266, 273, 285, 286, 287, 290, 295, 298, 299
OFFSET
1,1
COMMENTS
Supersequence of A121495.
EXAMPLE
62 is in the sequence because A120944(20)=62, A120944(21)=65, without primes between them.
MATHEMATICA
Select[Partition[Select[Range[400], CompositeQ[#]&&SquareFreeQ[#]&], 2, 1], PrimePi[ #[[1]]]==PrimePi[#[[2]]]&][[All, 1]] (* Harvey P. Dale, Apr 12 2020 *)
PROG
(PARI)
freesqrcomp(n)=issquarefree(n)&&!isprime(n)
nextfqc(n)={local(k); k=n+1; while(!freesqrcomp(k), k+=1); return(k)}
{for(i=2, 1000, if(freesqrcomp(i) && (nextfqc(i)<nextprime(i)), print1(i, ", ")))}
CROSSREFS
Sequence in context: A006625 A114382 A120141 * A121495 A263990 A253810
KEYWORD
nonn
AUTHOR
Antonio Roldán, Apr 08 2014
STATUS
approved