Many thanks Hans — and beautiful illustration! I will submit this sequence together with Kris Katterjohn in a couple of hours and link it to your blue spikes, if you don’t mind. Best, É. Catapulté de mon aPhone

Le 16 août 2020 à 14:39, Hans Havermann <gladhobo@bell.net> a écrit :

EA: "We start S with a(1) = 2 and always extend S with the product « nth digit x nth term of S ». (When the product is = 0, we don’t extend S with 0 but with the smallest integer not yet present in S.)"

See my graph of S to 10^5 here:

http://chesswanks.com/num/nthDigit*nthTerm.png

Large values in S are created by lengthy non-zero stretches in the digit list, appearing in the graph as spikes that culminate in a peak when the digit is again zero. Based only on the digit list for my calculated S, the peak at a(28385) can be predicted to be superseded by a slightly larger peak at a(350165). _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun