A035358 k such that A035312(k-1) = n or 0 if there is none.

1, 2, 3, 4, 11, 5, 7, 16, 6, 22, 8, 12, 17, 29, 37, 56, 9, 23, 46, 67, 79, 92, 13, 30, 18, 10, 106, 137, 38, 121, 24, 172, 154, 47, 57, 68, 211, 191, 232, 14, 80, 31, 93, 254, 277, 326, 352, 19, 107, 596, 301, 436, 39, 379, 407, 25, 122, 138, 466, 529, 155, 497, 48

Offset: 1

Author

Christian G. Bower, Nov 15 1998

Keywords

• nonn

Comments

At least up through the first 19 terms (ending at 46), this appears to be identical to the inverse of sequence A035312 considered as a permutation of the positive integers. - Howard A. Landman, Sep 23 2001

This sequence is *by definition* the inverse of A035312 (upon shifting its offset), provided that A035312 indeed is surjective on the positive integers. - M. F. Hasler, May 09 2013

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000
• A. C. Zorach, Additive triangle
• Reinhard Zumkeller, Haskell programs for sequences in connection with Zorach additive triangle
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A035311, A035312, A035313.

Programs

Haskell

-- See link for Haskell program.

Formula

a(n) = A000217(A072039(n) - 1) + A072038(n) if the sequence is in fact the inverse permutation of the flattened Zorach additive triangle. - Reinhard Zumkeller, Apr 30 2011