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 A084322 #5 Oct 15 2013 22:32:02 %S A084322 2,23,547,2357,4359293547691,325798243129564339, %T A084322 3947306373286437248759663633906484193454376823 %N A084322 Fixed points if prime-factor-concatenation function (A084318) is iterated at primorial number initial values. %F A084322 a(n)=A084318[A002110(n)] %e A084322 n=4: primorial[4]=2310; a(4)=4359293547691=A084318[2310]; the list of iterations: %e A084322 {2310, 235711, 7151223, 34495309, 41841349, 1116722777, 1958774883, 313113444469, 744730492067, 4359293547691}; %e A084322 at each step the ordered prime factors of previous term are concatenated. %t A084322 ffi[x_] := Flatten[FactorInteger[x]] ba[x_] := Table[Part[ffi[x], 2*w-1], {w, 1, lf[x]}] q[x_] := Apply[Times, Table[Prime[w], {w, 1, x}]] lf[x_] := Length[FactorInteger[x]] nd[x_, y_] := 10*x+y tn[x_] := Fold[nd, 0, x] coc[x_] := Fold[nd, 0, Flatten[IntegerDigits[ba[x]], 1]] Table[FixedPoint[coc, q[w]], {w, 1, 7}] %Y A084322 Cf. A001405, A084317, A084318. %K A084322 base,nonn %O A084322 1,1 %A A084322 _Labos Elemer_, Jun 20 2003