cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A265348 Inverse permutation to A265347.

Original entry on oeis.org

1, 2, 3, 4, 10, 5, 6, 7, 15, 9, 55, 8, 28, 44, 66, 11, 91, 20, 36, 13, 21, 14, 210, 12, 45, 35, 105, 19, 406, 27, 190, 22, 435, 230, 703, 26, 253, 299, 78, 18, 1711, 170, 325, 76, 741, 54, 496, 17, 136, 377, 528, 43, 820, 119, 276, 25, 153, 65, 2145, 34, 300, 209, 120, 16, 1596, 77, 231, 64, 1128, 104, 1770, 33, 351, 275, 171, 53, 2775, 90, 378, 24, 861
Offset: 1

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Author

Antti Karttunen, Dec 18 2015

Keywords

Crossrefs

Inverse: A265347.

Programs

  • Scheme
    (define (A265348 n) (let ((row (A265911 n)) (col (A265331 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))

Formula

a(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where c = A265331(n), and r = A265911(n).