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A083140 Sieve of Eratosthenes arranged as an array and read by antidiagonals in the up direction; n-th row has property that smallest prime factor is prime(n). +0
14
2, 3, 4, 5, 9, 6, 7, 25, 15, 8, 11, 49, 35, 21, 10, 13, 121, 77, 55, 27, 12, 17, 169, 143, 91, 65, 33, 14, 19, 289, 221, 187, 119, 85, 39, 16, 23, 361, 323, 247, 209, 133, 95, 45, 18, 29, 529, 437, 391, 299, 253, 161, 115, 51, 20, 31, 841, 667, 551, 493, 377, 319, 203 (list; table; graph; listen)
OFFSET

2,1

COMMENT

A permutation of natural numbers >= 2.

LINKS

Index entries for sequences that are permutations of the natural numbers

Index entries for sequences generated by sieves

EXAMPLE

Array begins:

2 4 6 8 10 12 14 16 18 20 22 24 .... (A005843)

3 9 15 21 27 33 39 45 51 57 63 69 .... (A016945)

5 25 35 55 65 85 95 115 125 145 155 175 .... (A084967)

7 49 77 91 119 133 161 203 217 259 287 301 .... (A084968)

11 121 143 187 209 253 319 341 407 451 473 517 .... (A084969)

13 169 221 247 299 377 403 481 533 559 611 689 .... (A084970)

MATHEMATICA

a = Join[ {Table[2n, {n, 1, 12}]}, Table[ Take[ Prime[n]*Select[ Range[100], GCD[ Prime[n] #, Product[ Prime[i], {i, 1, n - 1}]] == 1 &], 12], {n, 2, 12}]]; Flatten[ Table[ a[[i, n - i]], {n, 2, 12}, {i, n - 1, 1, -1}]]

CROSSREFS

Cf. A083141 (main diagonal), A083221 (transpose), A004280, A038179, A084967, A084968, A084969, A084970, A084971.

Adjacent sequences: A083137 A083138 A083139 this_sequence A083141 A083142 A083143

Sequence in context: A119586 A095904 A096153 this_sequence A124652 A048623 A075161

KEYWORD

nonn,tabl,nice

AUTHOR

Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp), Jun 05 2003

EXTENSIONS

More terms from Hugo Pfoertner (hugo(AT)pfoertner.org) and Robert G. Wilson v (rgwv(AT)rgwv.com), Jun 13 2003

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Last modified October 13 02:37 EDT 2008. Contains 145008 sequences.


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