A166091 Square array A(row>=0, col>=0) = (A166092(row,col)-3)/4, listed antidiagonally as A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), ...

0, 1, 2, 3, 79, 4, 5, 151, 8, 103, 7, 175, 14, 409, 22, 9, 223, 15, 589, 43, 10, 11, 265, 25, 998, 143, 31, 12, 13, 275, 32, 1297, 157, 73, 20, 16, 17, 283, 62, 1364, 182, 158, 55, 28, 6, 19, 361, 69, 1891, 293, 164, 183, 34, 26, 52, 21, 373, 74, 1952, 397, 401

Offset

0,3

Comments

Note: This is not a permutation of nonnegative integers, as for some odd n, A166040(n) gets even value, the first example being A166040(49)=32, thus 24 (= (49-1)/2) is missing from here, and correspondingly, 99 (= 2*49 + 1) is missing from A166092. Sequence A165602 gives the natural numbers missing from this table.

Links

A. Karttunen, Table of n, a(n) for n = 0..10010

Example

The top left corner of the array:
0, 1, 3, 5, 7, 9, ...
2, 79, 151, 175, 223, 265, ...
4, 8, 14, 15, 25, 32, ...
103, 409, 589, 998, 1297, 1364, ...
22, 43, 143, 157, 182, 293, ...

Prog

(MIT/GNU Scheme)
(define (A166091 n) (A166091bi (A025581 n) (A002262 n)))
(define (A166091bi n k) (let ((m (A005408 k))) (let loop ((i 0) (n n)) (cond ((= m (A166086 i)) (if (zero? n) i (loop (1+ i) (-1+ n)))) (else (loop (1+ i) n))))))

Crossrefs

See A166092. The leftmost column: A166094. The first five rows: A165468, A166052, A166054, A166056, A166058. Cf. also A112060.

Sequence in context: A377690 A306195 A091825 * A371141 A370993 A371228

Adjacent sequences: A166088 A166089 A166090 * A166092 A166093 A166094

Keyword

nonn,tabl

Author

Antti Karttunen, Oct 08 2009

Status

approved