This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A069618 #6 May 21 2025 19:00:29 %S A069618 6,61,461,46133,246133,2461337,22461337,224613371,12224613371, %T A069618 1222461337117,151222461337117,15122246133711733,615122246133711733, %U A069618 615122246133711733213,9615122246133711733213,961512224613371173321349 %N A069618 a(1) = 6; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes. %e A069618 a(4) = 46133 starting with a(3) = 461 and a(5) = 246133 in a(4) = 46133. %Y A069618 Cf. A053582, A069605, A069606, A069607, A069608, A069609, A069610, A069611, A069613, A069614, A069615, A069616, A069617. %K A069618 nonn,base %O A069618 1,1 %A A069618 _Amarnath Murthy_, Mar 27 2002 %E A069618 More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003