A100496 -id:A100496 - cp's OEIS frontend

A102497 Primes of the concatenated form 1nn1 where n is an integer >=0.

112121, 113131, 115151, 119191, 127271, 131311, 134341, 136361, 140401, 142421, 145451, 149491, 157571, 158581, 161611, 169691, 170701, 172721, 178781, 182821, 187871, 190901, 191911, 196961, 197971, 1100010001, 1100210021, 1101710171

Offset: 1

Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 12 2005

			112121 is prime and is of the form 1nn1 for n=12.
1100010001 is prime and is of the form 1nn1 for n=1000.

Cf. A100846; A100496 for the values of n that produce these primes.

A100497 Numbers n such that (2^n+1)^4-2 is a semiprime.

Original entry on oeis.org

0, 2, 3, 4, 6, 8, 10, 12, 16, 19, 22, 43, 44, 45, 52, 67, 76, 117, 130, 151, 169, 208, 232, 262

Offset: 1

Jonathan Vos Post, Nov 23 2004

a(20) >= 151. - Hugo Pfoertner, Jul 24 2019

a(25) >= 361. - Tyler Busby, Feb 17 2023

Status of (2^361+1)^4-2 in factordb.com.

Cf. A100496, n such that (2^n+1)^4-2 is prime.

Select[Range[0,130],PrimeOmega[(2^#+1)^4-2]==2&] (* Harvey P. Dale, Sep 02 2016 *)

Corrected by Hugo Pfoertner, Nov 25 2004

a(20)-a(24) from Tyler Busby, Feb 17 2023

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A102497 Primes of the concatenated form 1nn1 where n is an integer >=0.

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A100497 Numbers n such that (2^n+1)^4-2 is a semiprime.

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