A230041 Primes related to the strictly increasing subsequence of A053666.

2, 3, 5, 7, 19, 29, 37, 47, 59, 79, 89, 199, 269, 359, 379, 389, 479, 499, 599, 797, 887, 997, 1889, 1999, 2689, 2699, 2789, 2999, 3889, 3989, 4789, 4799, 4889, 4999, 6899, 8999, 25999, 27799, 28789, 28979, 29989, 37799, 37889, 39799, 39989, 48799, 48889

Offset: 1

Author

Shyam Sunder Gupta, Oct 06 2013

Keywords

• nonn
• base
• easy

Comments

a(1)=2; a(n+1) is the smallest prime with product of digits > product of digits of a(n).

From Wolfdieter Lang, Oct 31 2014: (Start)

A053666 is sieved as follows:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, ...

2, 3, 5, 7, 1, 3, 7, 9, 6, 18, 3, 21, 4, 12, 28, ...

2, 3, 5, 7, x, x, x, 9, x, 18, x, 21, x, x, 28,

and the related primes are:

2, 3, 5, 7, 19, 29, 37, 47, ...

(End)

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Examples

			a(6) = 29, product of digits is 18; a(7) = 37, product of digits is 21 and 21 > 18.
		

Links

• Shyam Sunder Gupta, Table of n, a(n) for n = 1..142

Crossrefs

Cf. A000040, A069802, A053666.

Programs

Mathematica

a = {}; t = 0; Do[s = Apply[Times, IntegerDigits[Prime[n]]]; If[s > t, t = s; AppendTo[a, Prime[n]]], {n, 1, 10^4}]; a

Extensions

Edited. Name specified. A000040, A053666 and 'easy' added by Wolfdieter Lang, Oct 31 2014