login
A276956
Inverse permutation to A276955.
3
1, 2, 3, 6, 10, 4, 15, 5, 21, 28, 36, 9, 45, 14, 55, 66, 78, 91, 105, 120, 136, 153, 171, 7, 190, 20, 210, 231, 253, 8, 276, 27, 300, 325, 351, 35, 378, 44, 406, 435, 465, 496, 528, 561, 595, 630, 666, 13, 703, 54, 741, 780, 820, 19, 861, 65, 903, 946, 990, 77, 1035, 90, 1081, 1128, 1176, 1225, 1275, 1326, 1378, 1431, 1485, 104
OFFSET
1,2
FORMULA
a(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where c = A276949(n), and r = A276951(n).
As a composition of other permutations:
a(n) = A257506(A275847(n)).
PROG
(Scheme) (define (A276956 n) (let ((row (A276951 n)) (col (A276949 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))
CROSSREFS
Inverse: A276955.
Related permutations: A257506, A275847.
Sequence in context: A353122 A058911 A249247 * A276946 A191542 A191668
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Sep 22 2016
STATUS
approved