A230085 - OEIS

A230085

Smallest of four consecutive primes whose product of digits is equal and nonzero.

336737123, 812444239, 1731191219, 2187575239, 2549315123, 2672459219, 2721498343, 2778476123, 2781452239, 2924114819, 2925926819, 3232115219, 3441686219, 3579455219, 3617846123, 3755345219, 3943951637

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

336737123 is in the sequence because 336737123, 336737161, 336737213 and 336737231 are consecutive primes and the product of the digits of each = 47628.

MATHEMATICA

a = {}; m = 1; s = 1; Do[If[(y = Apply[Times, IntegerDigits[x = Prime[n]]]) == s && s != 0, m = m + 1; If[m > 3, AppendTo[a, Prime[n - 3]]], m = 1]; s = y, {n, 1, 200000000}]; a

pdeQ[{a_, b_, c_, d_}]:=Module[{u=Union[Times@@@(IntegerDigits/@{a, b, c, d})]}, Length[ u] ==1&&u[[1]]>0]; Transpose[Select[Partition[Prime[Range[ 19*10^7]], 4, 1], pdeQ]][[1]] (* Harvey P. Dale, Jan 27 2015 *)

CROSSREFS

Cf. A230082, A230083, A230084, A007954, A053666.

Sequence in context: A271112 A337385 A233703 * A204337 A113739 A159448

Adjacent sequences: A230082 A230083 A230084 * A230086 A230087 A230088

KEYWORD

nonn,base

AUTHOR

Shyam Sunder Gupta, Oct 08 2013

STATUS

approved