A210734 Primes p such that p + 1 or p - 1 is a concatenation of successive even numbers starting from 2.

3, 23, 2467, 246809, 246811, 24681012141619, 24681012141618202224262830323436384041, 24681012141618202224262830323436384042444649

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: A009593 A351107 A009818 * A166315 A371346 A347680

Adjacent sequences: A210731 A210732 A210733 * A210735 A210736 A210737

Keyword

base,nonn

Author

Arkadiusz Wesolowski, May 10 2012

Status

approved