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A219958 Integers n such that n^2 can be represented as 2p + 3q with p and q primes not necessarily distinct. 4
4, 5, 7, 8, 10, 11, 13, 15, 17, 19, 20, 22, 23, 25, 27, 28, 29, 31, 32, 35, 37, 38, 40, 41, 43, 45, 47, 49, 53, 55, 59, 61, 63, 65, 67, 68, 70, 71, 73, 75, 77, 79, 82, 83, 85, 87, 89, 91, 92, 95, 97, 98, 101, 103, 105, 107, 109, 110, 112, 113, 115, 117, 118 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Zak Seidov, Table of n, a(n) for n = 1..115

EXAMPLE

4^2 = 16 = 2*5 + 3*2,

5^2 = 25 = 2*5 + 3*5,

7^2 = 49 = 2*5 + 3*13.

In case of multiple solutions (as for 5^2 and 7^2) just one solution (with least p) is shown.

MATHEMATICA

mx = 50000; Select[Sqrt[Union[Reap[Do[p = Prime[k]; Do[ Sow[ 2 Prime[i] + 3 p], {i, PrimePi[(mx - 3 p)/2]}], {k, PrimePi[(mx - 4)/3]}]][[2, 1]]]], IntegerQ]; (*for first 115 terms *)

CROSSREFS

Cf. A079026, A219955, A219956, A219957.

Sequence in context: A231507 A097482 A191984 * A288753 A202186 A247467

Adjacent sequences:  A219955 A219956 A219957 * A219959 A219960 A219961

KEYWORD

nonn

AUTHOR

Zak Seidov, Dec 02 2012

STATUS

approved

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Last modified August 23 14:00 EDT 2019. Contains 326229 sequences. (Running on oeis4.)