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A176864 Numbers k such that A053186(k) is prime. 5
3, 6, 7, 11, 12, 14, 18, 19, 21, 23, 27, 28, 30, 32, 38, 39, 41, 43, 47, 51, 52, 54, 56, 60, 62, 66, 67, 69, 71, 75, 77, 83, 84, 86, 88, 92, 94, 98, 102, 103, 105, 107, 111, 113, 117, 119, 123, 124, 126, 128, 132, 134, 138, 140, 146, 147, 149, 151, 155, 157, 161, 163 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers of the form p + j^2 where p is prime and p <= 2*j. - Robert Israel, Dec 14 2018

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

3-1^2=2, 6-2^2=2, 7-2^2=3, 11-3^2=2, ...

MAPLE

N:= 30: # to get all terms < (N+1)^2

Primes:= select(isprime, [2, seq(i, i=3..2*N, 2)]):

seq(op(map(`+`, select(`<=`, Primes, 2*j), j^2)), j=1..N); # Robert Israel, Dec 14 2018

MATHEMATICA

lst={}; Do[p=n-Floor[Sqrt[n]]^2; If[PrimeQ[p], AppendTo[lst, n]], {n, 6!}]; lst

CROSSREFS

Cf. A053186.

Sequence in context: A269177 A269178 A120511 * A347793 A306718 A022550

Adjacent sequences: A176861 A176862 A176863 * A176865 A176866 A176867

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 27 2010

STATUS

approved

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Last modified January 27 13:15 EST 2023. Contains 359840 sequences. (Running on oeis4.)