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A068827 a(1) = 2; for n > 1, a(n) is the smallest prime > a(n-1) such that each successive digit in the concatenation of terms (that does not follow 9) is greater than the previous digit. 1
2, 3, 5, 7, 89, 127, 919, 1237, 8923, 8929, 8969, 12347, 89123, 89137, 89189, 89237, 89269, 89293, 89393, 89459, 89491, 89567, 89591, 89597, 89689, 89797, 89891, 89897, 91237, 91249, 123457, 891239, 891349, 891379, 891389, 891391 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Zak Seidov, Table of n, a(n) for n=1..1001

R. J. Mathar, Maple program.

Hugo van der Sanden, Perl program.

EXAMPLE

From Petros Hadjicostas, Jun 06 2020: (Start)

a(4) = 7 because 7 is the smallest prime such that, when it is concatenated to 235, we get 2357 and each successive digit is greater than the previous one.

a(5) = 89 because 89 is the smallest prime such that, when it is concatenated to 2357, we get 235789 and each successive digit is greater than the previous one.

a(6) = 127 because 127 is the smallest prime such that, when it is concatenated to 235789, we get 235789127 and each successive digit that does not follow 9 is greater than the previous one. (End)

CROSSREFS

Sequence in context: A264576 A070275 A171042 * A289755 A318202 A076406

Adjacent sequences:  A068824 A068825 A068826 * A068828 A068829 A068830

KEYWORD

nonn,base

AUTHOR

Amarnath Murthy, Mar 08 2002

EXTENSIONS

Edited by Larry Reeves (larryr(AT)acm.org), Jan 13 2003

Corrected and extended by Franklin T. Adams-Watters, R. J. Mathar, Zak Seidov and Hugo van der Sanden, May 12 2010

Name edited by Petros Hadjicostas, Jun 06 2020

STATUS

approved

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Last modified January 19 06:28 EST 2021. Contains 340266 sequences. (Running on oeis4.)