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 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #23 Feb 16 2021 01:03:18
%S 2,3,13,23,97,101,103,109,131,457,641,677,751,787,811,881,977,1019,
%T 1049,2719,2753,2777,2909,3067,3083,3203,3329,3331,3547,3557,3613,
%U 3767,3823,3833,3847,3911,3929,4007,4159,4219,4259,4327,4421,4591,4639
%N Primes p such that prime(p-1) mod (p-1) = (prime(p) mod p) - 1.
%C Primes p such that A004648(p-1) + 1 = A004648(p).
%e 2 is a term because 2 is prime and A004648(2-1) = A004648(2)-1 = 0.
%o (Sage) A004648 = lambda n: nth_prime(n) % n
%o is_A177746 = lambda n: is_prime(n) and A004648(n) == A004648(n-1)+1 # _D. S. McNeil_, Dec 12 2010
%o (PARI) s=[]; forprime(n=2, 5000, if(prime(n-1)%(n-1) == prime(n)%n-1, s=concat(s, n))); s \\ _Colin Barker_, Jun 27 2014
%Y Cf. A000040, A004648.
%K nonn,less
%O 1,1
%A _Juri-Stepan Gerasimov_, Dec 12 2010
%E Corrected and extended by _D. S. McNeil_, Dec 12 2010