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A115408
Integer permutation induced by A024431.
5
1, 6, 15, 3, 2, 5, 4, 28, 45, 10, 66, 9, 14, 91, 13, 8, 7, 120, 12, 11, 153, 190, 21, 231, 276, 20, 325, 378, 435, 496, 27, 561, 630, 26, 703, 19, 780, 18, 861, 946, 1035, 17, 16, 25, 1128, 24, 1225, 1326, 1431, 23, 22, 1540, 1653, 36, 1770, 1891, 2016, 2145
OFFSET
1,2
COMMENTS
a(n) = A115406(n)*(A115406(n)-1)/2 + A115407(n) + 1;
inverse: A115409.
PROG
(Haskell)
import Data.List (elemIndex); import Data.Maybe (fromJust)
a115408 = (+ 1) . fromJust . (`elemIndex` a115409_list)
-- Reinhard Zumkeller, Sep 16 2014
CROSSREFS
Sequence in context: A013314 A328339 A019306 * A327602 A105052 A003566
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jan 22 2006
STATUS
approved