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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 (list; graph; refs; listen; history; text; internal format)
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(9n-8) p(9n-7) p(9n-6) p(9n-5) p(9n-4) p(9n-3) p(9n-2) p(9n-1) p(9n) n=1, 2, .. Right diagonal is p(9n-6 p(9n-4) p(9n-2)

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

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Last modified December 11 14:03 EST 2017. Contains 295884 sequences.