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A081053 Sum of a prime and the square of a prime. 3
6, 7, 9, 11, 12, 14, 15, 16, 17, 20, 21, 22, 23, 26, 27, 28, 30, 32, 33, 35, 36, 38, 40, 41, 42, 44, 45, 46, 47, 48, 50, 51, 52, 54, 56, 57, 60, 62, 63, 65, 66, 68, 70, 71, 72, 75, 76, 77, 78, 80, 82, 83, 84, 86, 87, 88, 90, 92, 93, 96, 98, 101, 102, 104, 105, 106, 107, 108 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Suggested by a Goldbach-type conjecture.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = p^2 + q, p and q primes.

EXAMPLE

7=2^2+3

MAPLE

G := proc(n::posint) local p, q; p := 2; while p<=n-2 do q := n-p^2; if type(q, posint) then if isprime(q) then return(true, p, q); end if; end if; p := nextprime(p); end do; return(false); end:

MATHEMATICA

Take[ Union[ Flatten[ Table[ Prime[i] + Prime[j]^2, {i, 1, 30}, {j, 1, 5}]]], 70]

PROG

(PARI) is(n)=if(n%2, isprime(n-4) || isprimepower(n-2)==2, forprime(q=3, sqrtint(n), if(isprime(n-q^2), return(1))); n==6) \\ Charles R Greathouse IV, Nov 01 2017

CROSSREFS

Sequence in context: A216361 A216360 A205877 * A022892 A120164 A074898

Adjacent sequences:  A081050 A081051 A081052 * A081054 A081055 A081056

KEYWORD

nonn

AUTHOR

Pilar Guerra Cardenas (pilarguerracardenas(AT)hotmail.com), Mar 03 2003

EXTENSIONS

More terms from Robert G. Wilson v, Mar 05 2003

STATUS

approved

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Last modified October 14 18:28 EDT 2019. Contains 328022 sequences. (Running on oeis4.)