A344549 Largest prime with strictly ascending consecutive digits in base n.

5, 11, 19, 569, 41, 2423, 207593, 23456789, 811, 160403, 95401, 235776949, 208888661909, 9927935178558959, 889872307619, 14707209648376466477, 1245691, 340387811, 96209320840499118292907, 9614505639105223858867, 1068038871569, 28923381229, 202821360694037, 409991957243270502360389

Offset: 3

Author

Hervé Loiseau, May 22 2021

Keywords

• nonn
• base

Comments

This sequence in ascending bases, starting with base 3: 12, 23, 34, 2345, 56, 4567, 345678, 23456789, 678, 789AB, 34567, 23456789, 56789ABCDE, 23456789ABCDEF, 789ABCDEFG, 23456789ABCDEFGH, 9ABCD, 56789AB, 3456789ABCDEFGHIJK, 3456789ABCDEFGHIJ, DEFGHIJKL, 6789ABCD, 23456789ABC, 9ABCDEFGHIJKLMNOP.

Examples

			12_3 = 5 is the largest prime number with strictly ascending digits for this base.
		

Crossrefs

Cf. A006055, A138141.

Programs

PARI

a(n)={forstep(k=n-1, 1, -1, forstep(j=n-k, 1, -1, my(t=fromdigits([j..j+k-1], n)); if(isprime(t), return(t)))); oo} \\ Andrew Howroyd, May 22 2021