A153660 Pairs of terms of A038512 which differ by 2.

527, 529, 899, 901, 1079, 1081, 1157, 1159, 1271, 1273, 1649, 1651, 1679, 1681, 1817, 1819, 1919, 1921, 1961, 1963, 2117, 2119, 2171, 2173, 2327, 2329, 2489, 2491, 2507, 2509, 2771, 2773, 2867, 2869, 2921, 2923, 3131, 3133, 3149, 3151, 3401, 3403, 3587, 3589

Offset

1,1

Comments

In each pair, the number in between (528, 900, etc.) is always divisible by 6. - Howard Berman (howard_berman(AT)hotmail.com), Jan 02 2009

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

527 = 17*31 and 529 = 23*23. Both are composite with no prime factor less than 13 and they differ by 2.

Mathematica

q[n_] := AllTrue[n + {0, 2}, CompositeQ[#] && FactorInteger[#][[1, 1]] >= 13 &]; Flatten @ Outer[Plus, Select[Range[3500], q], {0, 2}] (* Amiram Eldar, Mar 22 2021 *)

Crossrefs

Cf. A038512.

Sequence in context: A204472 A264804 A093226 * A337779 A261075 A250754

Adjacent sequences: A153657 A153658 A153659 * A153661 A153662 A153663

Keyword

nonn

Author

Howard Berman (howard_berman(AT)hotmail.com), Dec 30 2008

Extensions

More terms from Amiram Eldar, Mar 22 2021

Status

approved