A358180 Indices for A358168.
1, 30, 162, 1150, 11603, 104511, 1041245, 10226995, 101514698, 1008495923, 10060201866
Offset: 1
Programs
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Mathematica
nn = 2^20; q[] = False; q[0] = True; a[] = 0; c[] = -1; c[0] = 2; m = 1; {1}~Join~Reap[Do[j = c[m]; a[n] = m; c[m] = n; m = 0; If[j > 0, m = n - j]; If[! q[#2], Sow[n]; q[#2] = True] & @@ {a[n], IntegerLength[a[n]]}, {n, 3, nn}] ][[-1, -1]] (* _Michael De Vlieger, Nov 05 2022 *)
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Python
from itertools import count def A358180(n): b, bdict, k = 0, {0:(1,)},10**(n-1) if n > 1 else 0 for m in count(2): if b >= k: return m-1 if len(l := bdict[b]) > 1: b = m-1-l[-2] if b in bdict: bdict[b] = (bdict[b][-1],m) else: bdict[b] = (m,) else: b = 0 bdict[0] = (bdict[0][-1],m) # Chai Wah Wu, Nov 05 2022
Extensions
a(8) from Michael De Vlieger, Nov 05 2022
a(9)-a(10) from Chai Wah Wu, Nov 05 2022
a(11) from Martin Ehrenstein, Nov 05 2022
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