

A215641


Smallest prime whose decimal expansion consists of the concatenation of a 1digit prime, a 2digit prime, a 3digit prime, ..., and an ndigit prime.


12



2, 211, 211151, 2111011129, 211101100910009, 211101100910007100049, 2111011009100071000031000453, 211101100910007100003100000310000721, 211101100910007100003100000310000019100000543, 2111011009100071000031000003100000191000000071000000531
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OFFSET

1,1


COMMENTS

It is a plausible conjecture that a(n) always exists.
a(n) has A000217(n) = n*(n+1)/2 digits.


LINKS

Table of n, a(n) for n=1..10.


EXAMPLE

a(4) = 2111011129, the smallest prime formed from a singledigit, a doubledigit, a tripledigit, and a quadrupledigit prime, i.e., 2, 11, 101, 1129.


CROSSREFS

Cf. A000040, A000217, A003617.
Subsequence of A195302.
Cf. A338968 (similar with largest prime).
Sequence in context: A167839 A107612 A068814 * A195335 A090560 A181903
Adjacent sequences: A215638 A215639 A215640 * A215642 A215643 A215644


KEYWORD

nonn,base


AUTHOR

Jonathan Vos Post, Aug 18 2012


EXTENSIONS

Edited by N. J. A. Sloane, Aug 18 2012


STATUS

approved



