A176822 Primes p with at least one decimal digit 2 that remain prime after removing all 2's.

23, 127, 211, 223, 227, 241, 271, 283, 421, 523, 823, 829, 1021, 1123, 1201, 1213, 1223, 1229, 1231, 1237, 1249, 1279, 1291, 1297, 1321, 1327, 1429, 1627, 1723, 2003, 2011, 2017, 2027, 2053, 2083, 2089, 2113, 2129, 2131, 2137, 2179, 2203, 2207, 2213, 2237, 2243, 2267, 2273, 2297, 2311

Offset

1,1

Links

Table of n, a(n) for n=1..50.

Mathematica

Reap[Do[id=IntegerDigits[p=Prime[n]]; If[MemberQ[id, 2]&&PrimeQ[FromDigits[DeleteCases[id, 2]]], Sow[p]], {n, 3000}]][[2, 1]]

Prog

(Magma) remove2:=func< n | [ d: d in n | d ne 2 ] >; [ p: p in PrimesUpTo(3000) | exists(t){ d: d in D | d eq 2 } and IsPrime(Seqint(remove2(D))) where D is Intseq(p) ];

Crossrefs

Sequence in context: A044736 A033211 A142518 * A157146 A232827 A217496

Adjacent sequences: A176819 A176820 A176821 * A176823 A176824 A176825

Keyword

nonn,base

Author

Zak Seidov, Dec 07 2010

Status

approved