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A089298 Smallest prime with digit product 10^n. 5

%I #6 Mar 14 2015 17:54:23

%S 11,251,14551,155581,4545551,45555581,555555881,44555555581,

%T 455555558581,5555555888551,255555555585881,14555555558558851,

%U 155555555858885551,2555555555558885851,45555555555585855881

%N Smallest prime with digit product 10^n.

%C These numbers may not contain the digits {0, 3, 6, 7 or 9} and must end with the digit 1. Also the number of 2's plus half the number of 4's plus a quarter of the number of 8's must equal the number of 5's which in turn must equal n. - _Robert G. Wilson v_, Nov 06 2003

%e a(4) = 4545551 and the digit product = 10^4.

%t NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; a = Table[0, {10}]; p = 2; Do[ q = Log[10, Times @@ IntegerDigits[p]]; If[q != 0 && IntegerQ[q] && a[[q]] == 0, a[[q]] = p; Print[q, " = ", p]]; p = NextPrim[p], {n, 1, 10^9}]; a

%Y Cf. A089365, A088653, A090840, A091465, A090841.

%K base,nonn

%O 0,1

%A _Amarnath Murthy_, Oct 30 2003

%E Edited, corrected and extended by _Robert G. Wilson v_, Nov 06 2003

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Last modified April 19 07:38 EDT 2024. Contains 371782 sequences. (Running on oeis4.)