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A176822 Primes p with at least one decimal digit 2 that remain prime after removing all 2's. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)