A226073 - OEIS

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A226073

Numbers k such that triangular(k)-1 is a square and triangular(k)+1 is a prime number.

2

1, 4, 148, 5821348, 13748537282247342677718148, 49900608324196518198677680899235165296598423281799348

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OFFSET

1,2

COMMENTS

a(7) has 191 decimal digits: 314305920...194453348.

Corresponding primes and roots of squares: A226072 and A226074.

LINKS

Table of n, a(n) for n=1..6.

CROSSREFS

Cf. A226069-A226074.

Sequence in context: A160470 A350985 A269136 * A366218 A361774 A294826

Adjacent sequences: A226070 A226071 A226072 * A226074 A226075 A226076

KEYWORD

nonn

AUTHOR

Alex Ratushnyak, May 25 2013

STATUS

approved