A032597 Third of three consecutive palindromes all of which are prime.

1880881, 1881881, 1970791, 3591953, 7821287, 108505801, 159202951, 160717061, 175111571, 187111781, 316707613, 319414913, 725606527, 728909827, 731919137, 904101409, 921212129, 930515039, 987212789, 987505789, 10457075401, 10745154701

Offset: 1

Author

Patrick De Geest, May 15 1998

Keywords

• nonn
• base

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
• P. De Geest, World!Of Palindromic Primes

Crossrefs

Cf. A002385, A032595, A032596.

Programs

PARI

nxt(n)=my(d=digits(n)); i=(#d+1)\2; while(i&&d[i]==9, d[i]=0; d[#d+1-i]=0; i--); if(i, d[i]++; d[#d+1-i]=d[i], d=vector(#d+1); d[1]=d[#d]=1); sum(i=1, #d, 10^(#d-i)*d[i]) \\ From David A. Corneth at A002113
list(lim)=my(v=List(),p=1,q=2,r=3); while(r<=lim\=1, if(isprime(r), if(isprime(q), if(isprime(p), listput(v,r)); p=q; q=r; r=nxt(r), q=nxt(p=r); r=nxt(q)), q=nxt(p=nxt(r)); r=nxt(q))); Vec(v) \\ Charles R Greathouse IV, Aug 11 2021

Extensions

New name from Charles R Greathouse IV, Aug 11 2021