

A268146


Twin prime pairs concatenated to their average in decimal representation (the greater twin prepended, the lesser appended).


0



543, 765, 131211, 191817, 313029, 434241, 616059, 737271, 103102101, 109108107, 139138137, 151150149, 181180179, 193192191, 199198197, 229228227, 241240239, 271270269, 283282281, 313312311, 349348347, 421420419, 433432431, 463462461, 523522521, 571570569, 601600599
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OFFSET

1,1


COMMENTS

The greater prime of a twin prime pair is prepended and the lesser one is appended to their average (nonprime, interprime).
a(n) mod 3 = 0, (See A095958).


LINKS

Table of n, a(n) for n=1..27.


EXAMPLE

a(1)=543: the greater prime {5} of the first twin prime pair {3, 5} is prepended and the lesser prime {3} is appended to their average {4}.


MATHEMATICA

UpToN[k_]:=FromDigits//@ StringJoin//@ ToString/@ {#+1, #, #1} &/@ Select[ Table[ Prime[n]+1, {n, 2, PrimePi[k]}], PrimeQ[#+1] &]; UpToN[10000]


CROSSREFS

Cf. A001097, A014574, A095958, A111875, A268145.
Sequence in context: A232707 A334771 A163764 * A074888 A250854 A250685
Adjacent sequences: A268143 A268144 A268145 * A268147 A268148 A268149


KEYWORD

nonn,base,easy


AUTHOR

Mikk Heidemaa, Jan 27 2016


STATUS

approved



