A240593 The smaller of a pair of consecutive composite squarefree numbers (A120944) without any prime number between them.

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

Author

Antonio Roldán, Apr 08 2014

Keywords

• nonn

Comments

Supersequence of A121495.

Examples

			62 is in the sequence because A120944(20)=62, A120944(21)=65, without primes between them.
		

Crossrefs

Cf. A120944, A240592.

Programs

Mathematica

Select[Partition[Select[Range[400],CompositeQ[#]&&SquareFreeQ[#]&],2,1], PrimePi[ #[[1]]]==PrimePi[#[[2]]]&][[All,1]] (* Harvey P. Dale, Apr 12 2020 *)

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)