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A210734 Primes p such that p + 1 or p - 1 is a concatenation of successive even numbers starting from 2. 2
3, 23, 2467, 246809, 246811, 24681012141619, 24681012141618202224262830323436384041, 24681012141618202224262830323436384042444649 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(9) has 625 digits, a(10) has 1476 digits, a(11) has 5048 digits, a(12) has 39024 digits.

LINKS

Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10

G. L. Honaker, Jr. and Chris Caldwell, 24681...50451 (625-digits)

Henri & Renaud Lifchitz, PRP Records

MATHEMATICA

lst = {}; c = 0; Do[c = c*10^IntegerLength[n] + n; a = c - 1; If[PrimeQ[a], AppendTo[lst, a]]; b = c + 1; If[PrimeQ[b], AppendTo[lst, b]], {n, 2, 48, 2}]; lst

CROSSREFS

Cf. A019520.

Sequence in context: A088056 A009593 A009818 * A166315 A113577 A224700

Adjacent sequences:  A210731 A210732 A210733 * A210735 A210736 A210737

KEYWORD

base,nonn

AUTHOR

Arkadiusz Wesolowski, May 10 2012

STATUS

approved

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Last modified February 20 20:55 EST 2019. Contains 320345 sequences. (Running on oeis4.)