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A220953 Primes p such that floor(sqrt(2)) + floor(sqrt(3)) + floor(sqrt(5)) + ... + floor(sqrt(p)) is prime. 1
3, 29, 61, 73, 127, 181, 229, 251, 281, 313, 367, 487, 503, 509, 547, 587, 599, 601, 613, 617, 659, 727, 739, 751, 797, 809, 829, 863, 881, 983, 1033, 1061, 1087, 1103, 1153, 1163, 1223, 1277, 1381, 1861, 1871, 2039, 2063, 2099, 2113, 2131, 2203, 2221 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..48.

MATHEMATICA

ps = Prime[Range[1000]]; t = {}; s = 0; Do[s = s + Floor[Sqrt[p]]; If[PrimeQ[s], AppendTo[t, p]], {p, ps}]; t (* T. D. Noe, Feb 21 2013 *)

PROG

(PARI) s=0; forprime(p=2, 1e4, if(isprime(s+=sqrtint(p)), print1(p", "))) \\ Charles R Greathouse IV, Feb 21 2013

(MAGMA) [NthPrime(i): i in [1..400] | IsPrime(S) where S is &+[Floor(Sqrt(NthPrime(k))): k in [1..i]]]; // Bruno Berselli, Feb 21 2013

CROSSREFS

Cf. A062048.

Sequence in context: A210360 A049437 A171409 * A031912 A119951 A296246

Adjacent sequences:  A220950 A220951 A220952 * A220954 A220955 A220956

KEYWORD

nonn

AUTHOR

Daniel J. Hardisky, Feb 20 2013

STATUS

approved

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Last modified October 22 19:53 EDT 2019. Contains 328319 sequences. (Running on oeis4.)