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 A046253 #54 Sep 04 2025 18:40:53
%S A046253 0,1,3435,438579088
%N A046253 Equal to the sum of its nonzero digits raised to its own power.
%C A046253 A variant of Münchausen numbers, cf. A166623.
%C A046253 The sequence is finite, because the sum can't exceed 9^9*L < 10^9*L, where L is the number of digits, and for L > 10 this is less than the number N >= 10^(L-1). - _M. F. Hasler_, Oct 01 2024
%D A046253 J. S. Madachy, "Madachy's Mathematical Recreations", Dover N.Y., pp. 163-175.
%D A046253 C. A. Pickover, "Keys to Infinity", Wiley 1995, Ch. 22, pp. 169-171.
%D A046253 Alfred S. Posamentier, Math Charmers, Tantalizing Tidbits for the Mind, Prometheus Books, NY, 2003, page 37.
%D A046253 David Wells, "Curious and Interesting Numbers", Penguin 1988, pp. 169, 190.
%H A046253 Devin Akman, <a href="https://projecteuclid.org/euclid.mjms/1534384947">Munchausen Numbers Redux</a>, Missouri J. Math. Sci. 30 (2018), no. 1, 1--4.
%H A046253 Geoff Bailey, <a href="https://homepage.kranzky.com/puzzles/power_ultra.c">C program for the sequence</a> (cf. Hutchens link for more info), Aug. 1998.
%H A046253 Daan van Berkel, <a href="http://arxiv.org/abs/0911.3038">On a curious property of 3435</a>, arXiv:0911.3038 [math.HO], 2009.
%H A046253 Jason Hutchens, <a href="https://homepage.kranzky.com/puzzles/Power.html">power summation</a> (originally at ciips.ee.uwa.edu.au/~hutch), 1997.
%H A046253 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MuenchhausenNumber.html">Münchhausen Number</a>.
%e A046253 3435 = 3^3 + 4^4 + 3^3 + 5^5.
%t A046253 Select[Range[0,10000],Total[#^#&/@DeleteCases[IntegerDigits@#,0]]==#&] (* _Giorgos Kalogeropoulos_, May 08 2019 *)
%o A046253 (C) // See Bailey and Hutchens links
%o A046253 (PARI) select( {is_A046253(n)=n==A045512(n)}, [0..10^4]) \\ To find the 4th solution, multiply the set by 51817. - _M. F. Hasler_, Oct 01 2024
%Y A046253 Cf. A032799, A166623.
%Y A046253 Fixed points of A045512. See also A045503 (includes zero digits).
%K A046253 nonn,fini,full,base,changed
%O A046253 1,3
%A A046253 _Patrick De Geest_, May 15 1998