

A187871


a(1)=1; for n > 1, a(n) is the smallest number that is formed by arranging the decimal numbers "1", "2", ..., "n" in some order so that the sum of every pair of adjacent numbers "i" "j" is prime.


1



1, 12, 123, 1234, 14325, 143256, 1234765, 12347658, 123476589, 10123476589, 1103211658947, 101121123476589, 11013432111276589, 1011211231458941367, 110134151432111276589, 10112112151431613476589, 1101316151417121123476589, 101121118131615141723476589
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OFFSET

1,2


COMMENTS

A051237 and A187869 are the sequence that result if in addition we require that the number begins with "1" and ends with "n".


LINKS

Table of n, a(n) for n=1..18.
Claudio Meller, Lineas con numeros de 1 a n.
Rémy Sigrist, PARI program for A187871


PROG

(PARI) See Links section.


CROSSREFS

Cf. A051237, A187869.
Sequence in context: A132943 A262576 A262575 * A187869 A262574 A159901
Adjacent sequences: A187868 A187869 A187870 * A187872 A187873 A187874


KEYWORD

nonn,base


AUTHOR

N. J. A. Sloane, Mar 14 2011


EXTENSIONS

a(6) to a(10) from Claudio Meller, Mar 14 2011
a(10) corrected by Nathaniel Johnston, Mar 15 2011
More terms from Rémy Sigrist, Nov 28 2021


STATUS

approved



