A030456 a(0) = 2; a(n) is smallest prime containing a(n-1) as substring.

2, 23, 223, 1223, 12239, 122393, 1223939, 12239393, 122393939, 1223939399, 12239393993, 122393939933, 12239393993311, 412239393993311, 8412239393993311, 78412239393993311, 2378412239393993311, 23784122393939933111, 2623784122393939933111, 26237841223939399331111

Offset

0,1

Links

Sean A. Irvine, Table of n, a(n) for n = 0..100 (first 17 terms from Zak Seidov)

Sean A. Irvine, Java program (github)

Mathematica

FromDigits /@ Nest[Append[#, Block[{p = NextPrime@ FromDigits@ #[[-1]], d}, While[Length@ SequencePosition[Set[d, IntegerDigits@ p], #[[-1]]] == 0, p = NextPrime@ p]; d]] &, {{2}}, 7] (* Michael De Vlieger, Feb 26 2018 *)

Crossrefs

Cf. A068167.

Sequence in context: A340296 A242904 A068167 * A357436 A069837 A376434

Adjacent sequences: A030453 A030454 A030455 * A030457 A030458 A030459

Keyword

nonn,base

Author

Patrick De Geest

Extensions

a(17) onward from Zak Seidov, Nov 02 2009

a(19) corrected by Andrew Howroyd, Feb 26 2018

a(17) onward corrected by Sean A. Irvine, Apr 01 2020

Status

approved