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 A089365 Smallest prime whose product of digits is 2^n. 7
 11, 2, 41, 181, 281, 1481, 881, 4481, 18481, 48281, 48481, 228881, 284881, 828881, 884881, 4448881, 4848881, 18848881, 24888881, 48888841, 88884881, 188888881, 888828881, 848888881, 4848488881, 4488888881, 18848888881, 28888884881 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Chai Wah Wu, Table of n, a(n) for n = 0..1000 EXAMPLE a(8) = 24481 and the digital product is 2^8. MATHEMATICA NextPrim[n_] := Block[{k = n + 1}, While[ ! PrimeQ[k], k++ ]; k]; a = Table[0, {24}]; p = 2; Do[q = Log[2, Times @@ IntegerDigits[p]]; If[q != 0 && IntegerQ[q] && a[[q]] == 0, a[[q]] = p; Print[q, " = ", p]]; p = NextPrim[p], {n, 1, 10^9}]  (* Robert G. Wilson v, Nov 08 2003 *) For a(8): a = Map[ FromDigits, Join[{0}, #, {1}] & /@ Permutations[{2, 8, 8 }]]; Min[ Select[a, PrimeQ[ # ] & ]] (* Robert G. Wilson v, Nov 08 2003 *) CROSSREFS Cf. A088653, A090840, A091465, A090841, A089298. Sequence in context: A298439 A095157 A110767 * A130217 A096044 A160464 Adjacent sequences:  A089362 A089363 A089364 * A089366 A089367 A089368 KEYWORD base,nonn AUTHOR Amarnath Murthy, Nov 07 2003 EXTENSIONS Edited, corrected and extended by Robert G. Wilson v, Nov 08 2003 a(24)-a(25) corrected by Chai Wah Wu, Aug 15 2017 STATUS approved

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Last modified May 9 20:59 EDT 2021. Contains 343746 sequences. (Running on oeis4.)