A214847 Primes that become emirps when their most-significant-digit is deleted.

113, 131, 137, 173, 179, 197, 271, 313, 317, 331, 337, 373, 379, 397, 431, 479, 571, 613, 617, 631, 673, 773, 797, 937, 971, 997, 1013, 1031, 1097, 1709, 1733, 1907, 2017, 2113, 2179, 2311, 2347, 2389, 2953, 2971, 3037, 3079, 3167, 3347, 3359, 3389, 3701, 3709

Offset: 1

Author

Kevin L. Schwartz and Christian N. K. Anderson, May 03 2013

Keywords

• nonn
• base
• less

Examples

			113 and 1013 are both in the sequence, because upon deletion they become 13, which is an emirp.
		

Links

• Christian N. K. Anderson, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A210498, A006567, A024770, A000040, A225235, A225234.

Programs

R

library(gmp); isemirp<-function(x) isprime(x) & (j=paste(rev(unlist(strsplit(as.character(x),split=""))),collapse=""))!=x & isprime(j);
no0<-function(s){ while(substr(s,1,1)=="0" & nchar(s)>1) s=substr(s,2,nchar(s)); s}
i=as.bigz(0); y=as.bigz(rep(0,100)); len=0;
while(len<100)
if(isemirp(as.bigz(no0(substr((i=nextprime(i)),2,200)))))
y[(len=len+1)]=i