

A105089


Sum of the primes in ordered 3 X 3 prime squares.


1



100, 401, 763, 1163, 1601, 2053, 2501, 3017, 3517, 3997, 4479, 5105, 5571, 6045, 6639, 7217, 7741, 8331, 8927, 9417, 9949, 10613, 11201, 11711, 12467, 13063, 13559, 14159, 14653, 15311, 15937, 16661, 17253, 17959, 18531, 19093, 19813, 20461
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OFFSET

1,1


COMMENTS

Partition the primes into consecutive and nonoverlapping groups of nine primes and take the total of each group.  Harvey P. Dale, Sep 06 2018


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000


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, ...


EXAMPLE

The first 3 X 3 prime square
2 3 5
7 11 13
17 19 23
adds up to 100 the first entry in the table.


MATHEMATICA

With[{nn=40}, Total/@Partition[Prime[Range[9nn]], 9]] (* or *) Table[ Total[ Prime[Range[9i8, 9i]]], {i, 40}] (* Harvey P. Dale, Sep 06 2018 *)


PROG

(PARI) sumsq3x3(n) = { local(x, j, s); forstep(x=0, n, 9, s=0; for(j=1, 9, s += prime(x+j); ); print1(s", ") ) }


CROSSREFS

Sequence in context: A250806 A250853 A017270 * A017510 A290654 A017642
Adjacent sequences: A105086 A105087 A105088 * A105090 A105091 A105092


KEYWORD

easy,nonn


AUTHOR

Cino Hilliard, Apr 07 2005


STATUS

approved



