A188443 Numbers not appearing in A178133, which gives the number of odd semiprimes between consecutive squares.

25, 33, 63, 66, 75, 88, 191, 269, 285, 309, 348, 379, 399, 400, 404, 413, 437, 443, 456, 548, 553, 594, 616, 638, 675, 684, 702, 724, 764, 810, 819, 823, 829, 843, 897, 901, 906, 907, 1000, 1031, 1041, 1068, 1075, 1159, 1200, 1230, 1241, 1255, 1279, 1280, 1281, 1300, 1323, 1332

Offset

1,1

Links

Table of n, a(n) for n=1..54.

Mathematica

lst={}; k=0; s=4; Do[If[OddQ[n]&&Last/@FactorInteger[n]=={1, 1}, If[n<s^2, k++, AppendTo[lst, k]; k=1; s++]], {n, 2*10^8}]; Complement[Range@3000, Union@lst]

Crossrefs

Cf. A178133.

Sequence in context: A269345 A134099 A129074 * A068411 A020160 A075452

Adjacent sequences: A188440 A188441 A188442 * A188444 A188445 A188446

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Apr 20 2011

Status

approved