A115377 - OEIS

%I #11 Feb 16 2025 08:33:00

%S 55,97,225,11260,11540

%N Numbers n such that the first n digits of sqrt(2) form a prime.

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConstantPrimes.html">Constant Primes</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PythagorassConstantDigits.html">Pythagoras's Constant Digits</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/IntegerSequencePrimes.html">Integer Sequence Primes</a>

%e First Pythagorean prime is 1414213562373095048801688724209698078569671875376948073, which has 55 digits.

%Y Cf. A002193.

%K nonn,base,more,changed

%O 1,1

%A _Eric W. Weisstein_, Jan 21 2006