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 #11 Jul 26 2024 12:33:31
%S 2,612113,5372126317,4818372912366173,21291981879276213799,
%T 912733515196363393600307,668334992181698187977197951,
%U 231879245133561335194866134641,933651219687395363156136052921903
%N a(n) = the resulting prime generated when the process described in A101115 is applied to A101117(n).
%e a(3) = 5372126317 because 5372126317 is the last prime that can be generated by successively prepending nonzero digits to A101117(3). A101117(3) is 7. A101116(3) indicates that 9 digits can be successively prepended to 7 generating a new prime each time. Doing so and giving preference to the smallest digit which meets the requirement, generates the following primes: 17, 317, 6317, 26317, 126317, 2126317, 72126317, 372126317, 5372126317.
%o (Python)
%o g = agen() # uses agen() and imports from A101116
%o print([next(g)[2] for n in range(1, 7)]) # _Michael S. Branicky_, Jun 24 2022
%Y Cf. A053583, A024785, A000040, A101115, A101116, A101117.
%K base,more,nonn
%O 1,1
%A Chuck Seggelin (seqfan(AT)plastereddragon.com), Dec 02 2004
%E a(7)-a(8) and typo corrected in a(6) from _Michael S. Branicky_, Jun 24 2022
%E a(9) from _Michael S. Branicky_, Jul 26 2024