|
|
A278507
|
|
Square array A(row,col) where row n lists the numbers removed in round n of Flavius sieve. Array is read by antidiagonals A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), ...
|
|
9
|
|
|
2, 4, 5, 6, 11, 9, 8, 17, 21, 15, 10, 23, 33, 37, 25, 12, 29, 45, 55, 51, 31, 14, 35, 57, 75, 85, 73, 43, 16, 41, 69, 97, 111, 121, 99, 61, 18, 47, 81, 115, 145, 159, 151, 127, 67, 20, 53, 93, 135, 171, 199, 211, 193, 163, 87, 22, 59, 105, 157, 205, 243, 267, 271, 247, 187, 103, 24, 65, 117, 175, 231, 283, 319, 343, 339, 303, 229, 123
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
A(1,col) = 2*col; for row > 1, A(row,col) = A278492(row-1,(col*(row+1))-1). [Note that unlike this array, A278492 uses zero-based indexing for its rows and columns.]
|
|
EXAMPLE
|
The top left corner of the array:
2, 4, 6, 8, 10, 12, 14, 16, 18, 20
5, 11, 17, 23, 29, 35, 41, 47, 53, 59
9, 21, 33, 45, 57, 69, 81, 93, 105, 117
15, 37, 55, 75, 97, 115, 135, 157, 175, 195
25, 51, 85, 111, 145, 171, 205, 231, 265, 291
31, 73, 121, 159, 199, 243, 283, 327, 367, 409
43, 99, 151, 211, 267, 319, 379, 433, 487, 547
61, 127, 193, 271, 343, 421, 483, 559, 631, 699
67, 163, 247, 339, 427, 519, 607, 691, 793, 879
87, 187, 303, 403, 523, 639, 739, 853, 963, 1081
|
|
PROG
|
(Scheme)
(define (A278507bi row col) (cond ((= 1 row) (* 2 col)) (else (A278492bi (- row 1) (+ -1 (* col (+ 1 row)))))))
;; Code for A278492bi given in A278492.
|
|
CROSSREFS
|
Column 1: A100287 (apart from its initial 1).
Cf. A255543 for analogous array for Lucky sieve.
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|