A288820 Indices of records in A288818.

1, 2, 23, 223, 233, 237, 2237, 2337, 22337, 23137, 23337, 23373, 23797, 223373, 223797, 231373, 233137, 233797, 2233797, 2313797, 2331373, 2333797, 2337379, 2337397, 2353797, 22353797, 22373797, 23137397, 23173797, 23313797, 23353797, 23373797

Offset: 1

Author

Hans Havermann, Jun 17 2017

Keywords

• nonn
• base

Comments

If one assumes that larger terms begin with 22 or 23, then a(54)-a(64) are: 223373733797, 223537373797, 231337373797, 231353673797, 231353733797, 231373733797, 233137337397, 233537373797, 233753733797, 235313733797, and 235373733797. - Hans Havermann, Jul 31 2017

Links

• Giovanni Resta, Table of n, a(n) for n = 1..53

Crossrefs

Cf. A288818, A288819 (records' value), A080670.

Programs

Mathematica

ric[d_, lp_] := Block[{p, e, i, j, n = Length@d}, If[n == 0, cnt++, If[d[[1]] > 0, Do[p = FromDigits@ Take[d, i]; If[p > lp && PrimeQ@p, ric[Take[d, i - n], p]; Do[e = Take[d, {i + 1, j}]; If[e[[1]] > 0 && e != {1}, ric[Take[d, j - n], p]], {j, i+1, n}]], {i, n}]]]]; a[n_] := (cnt = 0; ric[ IntegerDigits@ n, 1]; cnt); L = {1}; k = 1; bst = 0; While[Length@L < 18, v = a[++k]; If[v > bst, AppendTo[L, k]; bst = v]]; L (* Giovanni Resta, Jun 19 2017 *)