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 A371588 #25 Jul 21 2025 13:13:43 %S A371588 2,144,8,610,5358359254990966640871840, %T A371588 68330027629092351019822533679447, %U A371588 15156039800290547036315704478931467953361427680642,23770696554372451866815101694984845480039225387896643963981,119447720249892581203851665820676436622934188700177088360 %N A371588 Smallest Fibonacci number > 1 such that some permutation of its digits is a perfect n-th power. %C A371588 Subsequence of A370071 after reordering (as the sequence is not monotonic; e.g., a(2) > a(3) and a(8) > a(9)). Leading 0 digits are allowed in the perfect power. For example, a(4) = 610 since 016 = 2^4. (If leading 0 digits were not allowed, a(4) would be 160500643816367088.) %H A371588 Chai Wah Wu, <a href="/A371588/b371588.txt">Table of n, a(n) for n = 1..16</a> %e A371588 a(1) = 2 since 2 = 2^1. %e A371588 a(2) = 144 since 144 = 12^2. %e A371588 a(3) = 8 since 8 = 2^3. %e A371588 a(4) = 610 since 016 = 2^4. %e A371588 a(5) = 5358359254990966640871840 since 0735948608251696955804943 = 59343^5 %e A371588 a(6) = 68330027629092351019822533679447 since 00059398947526192142327360782336 = 62464^6. %o A371588 (Python) %o A371588 from itertools import count %o A371588 from sympy import integer_nthroot %o A371588 def A371588(n): %o A371588 a, b = 1, 2 %o A371588 while True: %o A371588 s = sorted(str(b)) %o A371588 l = len(s) %o A371588 m = int(''.join(s[::-1])) %o A371588 u = int(''.join(s)) %o A371588 for i in count(max(2,integer_nthroot(u,n)[0])): %o A371588 if (k:=i**n) > m: %o A371588 break %o A371588 t = sorted(str(k)) %o A371588 if ['0']*(l-len(t))+t == s: %o A371588 return b %o A371588 break %o A371588 a, b = b, a+b %Y A371588 Cf. A000045, A227875, A001597, A118715, A370071. %K A371588 nonn,base %O A371588 1,1 %A A371588 _Chai Wah Wu_, Mar 28 2024