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A065342
Triangle of sum of two primes: prime(n)+prime(k) with n >= k >= 1.
6
4, 5, 6, 7, 8, 10, 9, 10, 12, 14, 13, 14, 16, 18, 22, 15, 16, 18, 20, 24, 26, 19, 20, 22, 24, 28, 30, 34, 21, 22, 24, 26, 30, 32, 36, 38, 25, 26, 28, 30, 34, 36, 40, 42, 46, 31, 32, 34, 36, 40, 42, 46, 48, 52, 58, 33, 34, 36, 38, 42, 44, 48, 50, 54, 60, 62, 39, 40, 42, 44, 48
OFFSET
1,1
FORMULA
T(n, k) = 2*A065305(n, k) [but note different offset].
EXAMPLE
Sequence starts 2+2; 3+2, 3+3; 5+2, 5+3, 5+5; etc. i.e. 4; 5,6; 7,8,10; ...
Triangle begins:
4;
5, 6;
7, 8, 10;
9, 10, 12, 14;
13, 14, 16, 18, 22;
...
PROG
(Haskell)
import Data.List (inits)
a065342 n k = a065342_tabl !! (n-1) !! (k-1)
a065342_row n = a065342_tabl !! (n-1)
a065342_tabl = zipWith (map . (+)) a000040_list $ tail $ inits a000040_list
-- Reinhard Zumkeller, Aug 02 2015, Jan 30 2012
(PARI) row(n) = vector(n, k, prime(n)+prime(k)); \\ Michel Marcus, Sep 10 2021
CROSSREFS
Cf. A052147 (left edge), A100484 (right edge), A000040.
Cf. A087112.
Cf. A065305.
Sequence in context: A356824 A099070 A288658 * A231369 A251392 A076597
KEYWORD
nonn,tabl
AUTHOR
Henry Bottomley, Oct 30 2001
STATUS
approved