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%I #18 Aug 23 2019 03:33:37
%S 19,7625597484990,
%T 13407807929942597099574024998205846127479365820592393377723561443721764030073546976801874298166903427690031858186486050853753882811946569946433649006084099
%N Goodstein sequence starting with 19.
%C To calculate a(n), write a(n-1) in the hereditary representation base n+1, then bump the base to n+2, then subtract 1.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/GoodsteinSequence.html">Goodstein Sequence</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Goodstein's_theorem">Goodstein's Theorem</a>
%H Reinhard Zumkeller, <a href="/A211378/a211378.hs.txt">Haskell programs for Goodstein sequences</a>
%e The first terms are (see Wikipedia):
%e a(0) = 2^2^2 + 2^1 + 2^0 = 19
%e a(1) = 3^3^3 + 3^1 + 3^0 - 1 = 7625597484990
%e a(2) = 4^4^4 + 4^1 - 1 (155 digits)
%e a(3) = 5^5^5 + 3 - 1 (2185 digits)
%e a(4) = 6^6^6 + 2 - 1 (36306 digits)
%e a(5) = 7^7^7 + 1 - 1 (695975 digits)
%e a(6) = 8^8^8 - 1 (15151336 digits).
%o (Haskell) see Link
%Y Cf. A215409 (start=3), A056193 (start=4), A222117 (start=15), A059933 (start=16).
%K nonn,fini
%O 0,1
%A _Reinhard Zumkeller_, Feb 13 2013
%E Offset changed to 0 by _Nicholas Matteo_, Aug 21 2019
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