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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A224075 Triangle read by rows: n-th row gives the primes p of form (m - k^2) where m = A214583(n), k < m and gcd(k,m) = 1.

Original entry on oeis.org

2, 3, 5, 7, 11, 5, 13, 17, 11, 19, 23, 29, 7, 23, 31, 13, 29, 37, 17, 41, 23, 47, 5, 29, 53, 11, 59, 13, 37, 53, 61, 19, 43, 59, 67, 23, 47, 71, 31, 71, 79, 59, 83, 41, 89, 17, 73, 89, 97, 59, 83, 107, 29, 61, 101, 109, 83, 107, 131, 17, 89, 113, 137, 19, 59
Offset: 1

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Author

Reinhard Zumkeller, Mar 31 2013

Keywords

Comments

Defined where A214583 is defined.

Examples

			.   n | A214583 |  T(n,k) for k = 1 .. A224076(n)
. ----+---------+-------------------------------------------------------
.   1 |      3  |  [2]
.   2 |      4  |  [3]
.   3 |      6  |  [5]
.   4 |      8  |  [7]
.   5 |     12  |  [11]
.   6 |     14  |  [5,13]
.   7 |     18  |  [17]
.   8 |     20  |  [11,19]
.   9 |     24  |  [23]
.  10 |     30  |  [29]
.  11 |     32  |  [7,23,31]           32-5^2, 32-3^2, 32-1^2
.  12 |     38  |  [13,29,37]          38-5^2, 38-3^2, 38-1^2
.  13 |     42  |  [17,41]             42-5^2, 42-1^2
.  14 |     48  |  [23,47]             48-5^2, 48-1^2
.  15 |     54  |  [5,29,53]           54-7^2, 54-5^2, 54-1^2
.  16 |     60  |  [11,59]             60-7^2, 60-1^2
.  17 |     62  |  [13,37,53,61]       62-7^2, 62-5^2, 62-3^2, 62-1^2
.  18 |     68  |  [19,43,59,67]       68-7^2, 68-5^2, 68-3^2, 68-1^2
.  19 |     72  |  [23,47,71]          72-7^2, 72-5^2, 72-1^2
.  20 |     80  |  [31,71,79]          80-7^2, 80-3^2, 80-1^2
.  21 |     84  |  [59,83]             84-5^2, 83-1^2
.  22 |     90  |  [41,89]             90-7^2, 90-1^2
.  23 |     98  |  [17,73,89,97]       98-9^2, 98-5^2, 98-3^2, 98-1^2
.  24 |    108  |  [59,83,107]         108-7^2, 108-5^2, 108-1^2
.  25 |    110  |  [29,61,101,109]     110-9^2, 110-7^2, 101-3^2, 101-1^2
.  26 |    132  |  [83,107,131]        132-7^2, 132-5^2, 132-1^2
.  27 |    138  |  [17,89,113,137]     138-11^2, 138-7^2, ...
.  28 |    140  |  [19,59,131,139]     ...
.  29 |    150  |  [29,101,149]
.  30 |    180  |  [11,59,131,179]
.  31 |    182  |  [61,101,157,173,181]
.  32 |    198  |  [29,149,173,197]
.  33 |    252  |  [83,131,227,251]
.  34 |    318  |  [29,149,197,269,293,317]
.  35 |    360  |  [71,191,239,311,359]
.  36 |    398  |  [37,109,173,229,277,317,349,373,389,397]
.  37 |    468  |  [107,179,347,419,443,467]
.  38 |    570  |  [41,281,401,449,521,569]
.  39 |    572  |  [43,131,211,283,347,491,523,547,563,571]
.  40 |    930  |  [89,401,569,641,761,809,881,929]
.  41 |   1722  |  [353,761,881,1097,1193,1361,1433,1553,1601,1697,1721].
		

Crossrefs

Cf. A224076 (row lengths), A010051.

Programs

  • Haskell
    a224075 n k = a224075_tabf !! (n-1) !! (k-1)
    a224075_row n = a224075_tabf !! (n-1)
    a224075_tabf = f 3 where
       f x = g [] 3 1 where
         g ps i k2 | x <= k2        = ps : f (x + 1)
                   | gcd k2 x > 1   = g ps (i + 2) (k2 + i)
                   | a010051 q == 1 = g (q:ps) (i + 2) (k2 + i)
                   | otherwise      = f (x + 1)
                   where q = x - k2