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 A158320 a(1)=0, a(n) is the smallest nonprime > (n-1)^smallest digit of a(n-1). 0
 0, 4, 18, 4, 258, 26, 38, 344, 513, 10, 4, 14642, 14, 14, 15, 16, 18, 18, 20, 4, 160002, 4, 234257, 530, 4, 390626, 4, 531442, 30, 4, 810001, 4, 1048577, 4, 1336338, 36, 46657, 1874162, 39, 59320 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..40. EXAMPLE 0, 4(>1=1^0), 20(>18=2^4), 4(>1=3^0), 258(>256=4^4), 26(>25=5^2), 38(>36=6^2), 344(>343=7^3), 513(>512=8^3), 10(>9=9^1), 4(>1=10^1), 14642(>14641=11^4), 14(>12=12^1), 14(>13=13^1), 15(>14=14^1), 16(>15=15^1), 18(>16=16^1), 18(>17=17^1), 20(>18=18^1), 4(>1=19^0), ?(>160000=20^4) MATHEMATICA nxt[{n_, a_}]:=Module[{k=n^Min[IntegerDigits[a]]+1}, While [PrimeQ[k], k++]; {n+1, k}]; Transpose[NestList[nxt, {1, 0}, 40]][[2]] (* Harvey P. Dale, Apr 17 2015 *) CROSSREFS Cf. A000027, A141468. Sequence in context: A246133 A205014 A204936 * A342153 A341800 A236563 Adjacent sequences: A158317 A158318 A158319 * A158321 A158322 A158323 KEYWORD nonn,base,less AUTHOR Juri-Stepan Gerasimov, Mar 16 2009 EXTENSIONS Corrected (a(3) replaced by 18, duplicate of a(20) removed) and extended by R. J. Mathar, May 19 2010 Definition corrected by Harvey P. Dale, Apr 17 2015 STATUS approved

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Last modified September 10 06:17 EDT 2024. Contains 375773 sequences. (Running on oeis4.)