

A105090


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


0



36, 133, 253, 389, 533, 679, 841, 1007, 1175, 1327, 1489, 1703, 1859, 2021, 2209, 2405, 2571, 2769, 2977, 3139, 3319, 3545, 3733, 3905, 4135, 4361, 4525, 4721, 4891, 5099, 5319, 5549, 5743, 5987, 6177, 6361, 6599, 6813, 7021, 7193, 7425, 7675, 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(9n8) p(9n7) p(9n6) p(9n5) p(9n4) p(9n3) p(9n2) p(9n1) p(9n) n=1, 2, .. Left diagonal is p(9n8) p(9n4) p(9n)


EXAMPLE

The first 3 X 3 prime square
2 3 5
7 11 13
17 19 23
sum of left diagonal = 2 + 11 + 23 = 36 the first entry.


PROG

(PARI) sum3x3left(n) = { local(x, j, s); forstep(x=0, n, 9, s=0; forstep(j=1, 9, 4, s += prime(x+j); ); print1(s", ") ) }


CROSSREFS

Sequence in context: A260130 A155708 A196891 * A254284 A076578 A044368
Adjacent sequences: A105087 A105088 A105089 * A105091 A105092 A105093


KEYWORD

easy,nonn


AUTHOR

Cino Hilliard, Apr 07 2005


STATUS

approved



