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A157158 Primes where the first digit is equal to the largest digit. 0
2, 3, 5, 7, 11, 31, 41, 43, 53, 61, 71, 73, 83, 97, 101, 211, 311, 313, 331, 401, 421, 431, 433, 443, 503, 521, 523, 541, 601, 613, 631, 641, 643, 653, 661, 701, 727, 733, 743, 751, 757, 761, 773, 811, 821, 823, 827, 853, 857, 863, 877, 881, 883, 887, 907, 911 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The upper asymptotic density is 1/9 and the lower asymptotic density is 1/81, due to the Prime Number Theorem.

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

2(2=2), 3(3=3), 5(5=5), 7(7=7), 31(3=3>1), 41(4=4>1), 43(4=4>3), etc.

MAPLE

a := proc (n) local nn, nnn: nn := convert(ithprime(n), base, 10): nnn := seq(nn[j], j = 1 .. nops(nn)): if nn[nops(nn)] = max(nnn) then ithprime(n) else end if end proc: seq(a(n), n = 1 .. 200); # Emeric Deutsch, Mar 02 2009

CROSSREFS

Sequence in context: A028912 A075236 A155081 * A155833 A028867 A104154

Adjacent sequences:  A157155 A157156 A157157 * A157159 A157160 A157161

KEYWORD

nonn,base,less

AUTHOR

Juri-Stepan Gerasimov, Feb 24 2009

EXTENSIONS

11, 313 etc. inserted by Emeric Deutsch and R. J. Mathar, Feb 26 2009

STATUS

approved

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Last modified July 14 10:35 EDT 2020. Contains 335722 sequences. (Running on oeis4.)