A350278 Index of first occurrence of n in A349325.
1, 3, 6, 7, 14, 19, 54, 109, 110, 73, 146, 145, 328, 129, 342, 345, 398, 337, 462, 313, 3708, 353, 470, 14673, 5838, 10855, 23718, 14473, 60216, 26283, 60220, 60221, 500726, 155897, 1098404, 445089, 1098406, 1316099, 1168014, 1386505, 3932646, 1169865, 4424230
Offset: 1
Examples
a(5) = 14 because 5 occurs for the first time at position 14 in A349325.
Links
Programs
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Mathematica
A349325[n_]:=A349325[n]=Module[{h=1,c=n,prevc=n},While[c>1,If[OddQ[c],c=(3c+1)/2;If[prevc
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Python
def A349325(n): prevc = c = n h = 1 while c > 1: if c % 2: c = (3*c+1) // 2 if prevc < n and c > n: h += 1 else: c //= 2 if prevc > n and c < n: h += 1 prevc = c return h def A349325_fo_idx(n): i = 1 while A349325(i) != n: i += 1 return i print([A349325_fo_idx(n) for n in range(1, 20)])
Extensions
a(36)-a(43) from Chai Wah Wu, Jan 04 2022