A279968 - OEIS

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A279968

Square array read by antidiagonals upwards in which each term is the number of prior elements in the same row, column, diagonal, or antidiagonal whose parity is not the same as the parity of n.

0, 0, 2, 0, 4, 0, 3, 1, 4, 2, 3, 3, 5, 3, 4, 2, 3, 5, 5, 4, 7, 2, 4, 5, 5, 6, 8, 3, 5, 4, 5, 10, 7, 7, 7, 7, 5, 5, 5, 9, 6, 12, 6, 8, 9, 4, 5, 8, 6, 6, 10, 9, 9, 7, 10, 4, 6, 8, 8, 5, 13, 9, 9, 12, 12, 8, 7, 6, 7, 8, 10, 9, 10, 12, 7, 11, 14, 9

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Peter Kagey, Table of n, a(n) for n = 1..5000

EXAMPLE

The first six terms of this array are:

0 2 0

0 4

a(8) = 1 because the parity of 8 is different from the parity of a(7) = 1.

a(3) = 2 because the parity of 3 is different from the parity of a(2) = 0 and a(1) = 0.

PROG

(Haskell)

a279968 n = genericIndex a279968_list (n - 1)

a279968_list = map count [1..] where

count n = genericLength $ filter (odd . (n+)) adjacentLabels where

adjacentLabels = map a279968 (a274080_row n)

CROSSREFS

Cf. A279965 for the related sequence which counts same-parity prior elements.

Cf. also A279211, A279212.

Sequence in context: A259759 A364817 A119607 * A164297 A349240 A366879

Adjacent sequences: A279965 A279966 A279967 * A279969 A279970 A279971

KEYWORD

nonn,tabl

AUTHOR

Alec Jones, Dec 24 2016

STATUS

approved