A248745 Primes becoming a composite number if any digit is deleted (zeros allowed).

89, 227, 251, 257, 277, 281, 349, 409, 449, 499, 521, 557, 577, 587, 727, 757, 787, 821, 827, 857, 877, 881, 887, 991, 1117, 1129, 1171, 1187, 1259, 1289, 1423, 1447, 1453, 1471, 1483, 1543, 1553, 1559, 1583, 1621, 1669, 1721, 1741, 1747, 1777, 1847, 1889

Offset

1,1

Comments

Since J. Gutierrez called terms of A051362 "super-prime numbers", then it is natural to call the terms of this sequence "weakest primes".

Links

Peter J. C. Moses, Table of n, a(n) for n = 1..1000

Mathematica

compositeQ[n_]:=!(Abs[n]==1||PrimeQ[n]);
Select[Prime[Range[5, 500]], Apply[And, Map[compositeQ[FromDigits[#]]&, Subsets[#, {Length[#]-1}]&[IntegerDigits[#]]]]&] (* Peter J. C. Moses, Oct 13 2014 *)
Select[Prime[Range[300]], AllTrue[FromDigits/@Table[Drop[IntegerDigits[#], {k}], {k, IntegerLength[#]}], CompositeQ]&] (* Harvey P. Dale, Oct 30 2021 *)

Crossrefs

Cf. A051362, A000040.

Sequence in context: A217577 A142826 A251079 * A033257 A145821 A354284

Adjacent sequences: A248742 A248743 A248744 * A248746 A248747 A248748

Keyword

nonn,base

Author

Vladimir Shevelev, Oct 13 2014

Extensions

More terms from Peter J. C. Moses, Oct 13 2014

Status

approved