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A226217 Primes whose first digit is a square. 2
11, 13, 17, 19, 41, 43, 47, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 907, 911, 919, 929, 937, 941, 947, 953 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

K. D. Bajpai, Table of n, a(n) for n = 1..10000

EXAMPLE

a(8) =  97  which is a prime and its first digit is 9 that is a square number : 3^2.

MAPLE

KD := proc() local a, b, d, e; a:= ithprime(n); b:=length(a); d:=a/(10^(b-1)); e:=floor(d); if evalf(sqrt(e))=floor(evalf(sqrt(e))) then RETURN (a):fi; end:seq(KD(), n=1..200);

CROSSREFS

Cf. A223458 (similar sequence for Primes: first digit a composite number).

Sequence in context: A249376 A068155 A271367 * A275058 A157175 A132244

Adjacent sequences:  A226214 A226215 A226216 * A226218 A226219 A226220

KEYWORD

nonn,base

AUTHOR

K. D. Bajpai, Aug 24 2013

STATUS

approved

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Last modified December 7 17:41 EST 2019. Contains 329847 sequences. (Running on oeis4.)