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A089767
Squares which when concatenated with a 1 gives prime.
1
1, 4, 25, 49, 64, 81, 225, 400, 676, 784, 900, 1089, 1225, 1369, 1600, 1681, 2209, 2304, 3249, 3364, 4096, 5041, 6889, 7225, 7396, 8100, 8281, 8649, 9801, 10816, 11025, 11236, 12100, 12544, 12769, 13924, 15876, 16384, 17424, 19881, 21609, 21904
OFFSET
1,2
COMMENTS
Squares n such that 10*n+1 is prime. - Robert Israel, Dec 09 2017
LINKS
EXAMPLE
41, 4001, 6761 etc. are primes.
MAPLE
select(t -> isprime(10*t+1), map(`^`, [$1..300], 2)); # Robert Israel, Dec 09 2017
MATHEMATICA
Select[Range[150]^2, PrimeQ[10 # + 1] &] (* Michael De Vlieger, Dec 09 2017 *)
PROG
(MATLAB) A = []; count = 0; i = 1; while count < 60; s = i*i; if isprime(10*s + 1) A = [A s]; count = count + 1; end; i = i + 1; end; A
CROSSREFS
Intersection of A000290 and A024912.
Sequence in context: A335350 A199772 A245697 * A337173 A135784 A131069
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 23 2003
EXTENSIONS
Corrected and extended by David Wasserman, Feb 25 2004
STATUS
approved