A101118 - 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