The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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