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A121388 Table read by antidiagonals which classifies the proper odd numbers by form (i,j) where i and j are the number of prime factors of the form 4k-1 and 4k+1 respectively. 2
3, 5, 7, 9, 13, 11, 15, 21, 17, 19, 25, 35, 33, 29, 23, 27, 65, 39, 49, 37, 31, 45, 63, 85, 51, 57, 41, 43, 75, 105, 99, 145, 55, 69, 53, 47, 125, 175, 117, 147, 169, 87, 77, 61, 59, 81, 325, 195, 153, 171, 185, 91, 93, 73, 67, 135, 189, 425, 255, 165, 207, 205, 95, 121, 89 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..65.

EXAMPLE

Table begins:

Row(i,j)

1: (1,0) 3,7,11,19,23,31,43,47,59,67,71,79,83,103,... (A002145)

2: (0,1) 5,13,17,29,37,41,53,61,73,89,97,101,109,... (A002144)

3: (2,0) 9,21,33,49,57,69,77,93,121,129,133,141,... (A107978)

4: (1,1) 15,35,39,51,55,87,91,95,111,115,119,... (A080774)

5: (0,2) 25,65,85,145,169,185,205,221,265,289,... (A121387)

6: (3,0) 27,63,99,147,171,207,231,279,343,...

7: (2,1) 45,105,117,153,165,245,261,273,...

8: (1,2) 75,175,195,255,275,435,455,...

9: (0,3) 125,325,425,725,845,925,...

10:(4,0) 81,189,297,441,513,...

11:(3,1) 135,315,351,459,...

12:(2,2) 225,525,585,...

13:(1,3) 375,875,...

14:(0,4) 625,...

CROSSREFS

Cf. A120027. Subsequences begin A002145 A002144 A107978 A080774 A121387.

Sequence in context: A100432 A261033 A145341 * A161700 A245212 A063081

Adjacent sequences:  A121385 A121386 A121387 * A121389 A121390 A121391

KEYWORD

nonn,tabl

AUTHOR

Alford Arnold, Jul 26 2006

EXTENSIONS

Edited, corrected and extended by Ray Chandler, Aug 08 2010

STATUS

approved

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Last modified May 29 05:41 EDT 2022. Contains 354122 sequences. (Running on oeis4.)