A174358 Alternating triangle (version 3) read by rows: numbers k such that k=6*m+3-+2=r*j , r>=j and n>=q where r=6*n+3-2 or r=6*n+3+2 and j=6*q+3-2 or j=6*q+3+2.

5, 1, 25, 11, 35, 77, 7, 55, 49, 121, 17, 65, 119, 143, 221, 13, 85, 91, 181, 109, 289, 23, 95, 161, 209, 299, 323, 437, 19, 115, 133, 253, 247, 391, 361, 529, 29, 125, 203, 275, 377, 425, 551, 575, 725, 25, 145, 175, 319, 325, 493, 475, 667, 625, 841, 35, 185, 245

Offset: 1

Author

Juri-Stepan Gerasimov, Mar 17 2010, Mar 30 2010

Keywords

• nonn
• tabl

Comments

Numbers of form 6*m+3+2 are in even rows, numbers of form 6*m+3-2 are in odd rows. Numbers of alternating triangle (version 1) are A173865. Numbers of alternating triangle (version 2) are A174027.

Examples

			Triangle begins: 5*1 1*1 5*5 11*1 7*5 11*7 7*1 11*5 7*7 11*11 17*1 13*5 17*7 13*11 17*13 13*1 17*5 13*7 17*11 13*13 17*17.. or 5(in even 0 row) 1 25(in odd 1 row) 11 35 77(in even 2 row) 7 55 49 121(in odd 3 row) 17 65 119 143 221(in even 4 row) 13 85 91 181 169 289(in odd 5 row)..
That is:
5;
1, 25;
11, 35, 77;
7, 55, 49, 121;
17, 65, 119, 143;
		

Crossrefs

Cf. A007310, A173825, A173865, A174027.