

A105091


Sum of the right diagonal in ordered 3 X 3 prime squares.


0



33, 133, 253, 383, 537, 691, 829, 1003, 1169, 1333, 1495, 1703, 1855, 2015, 2217, 2417, 2589, 2781, 2977, 3143, 3313, 3537, 3725, 3899, 4157, 4349, 4511, 4713, 4871, 5113, 5317, 5563, 5747, 5987, 6183, 6377, 6607, 6827, 7025, 7187, 7391, 7673, 7927
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..43.


FORMULA

An ordered 3 X 3 prime square is 9 consecutive primes arranged in a square of the form p(9n8) p(9n7) p(9n6) p(9n5) p(9n4) p(9n3) p(9n2) p(9n1) p(9n) n=1, 2, .. Right diagonal is p(9n6 p(9n4) p(9n2)


EXAMPLE

The first 3 X 3 prime square
2 3 5
7 11 13
17 19 23
sum of right diagonal = 5 + 11 + 17 = 33 the first entry.


PROG

(PARI) sum3x3right(n) = { local(x, j, s); forstep(x=0, n, 9, s=0; forstep(j=3, 7, 2, s += prime(x+j); ); print1(s", ") ) }


CROSSREFS

Sequence in context: A043502 A044365 A044746 * A158588 A232538 A231758
Adjacent sequences: A105088 A105089 A105090 * A105092 A105093 A105094


KEYWORD

easy,nonn


AUTHOR

Cino Hilliard, Apr 07 2005


STATUS

approved



