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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 6 13:24 EST 2021. Contains 349563 sequences. (Running on oeis4.)