A123679 - OEIS

A123679

a(n) = 2*n - A123088(n).

1, 0, 0, 1, 0, 1, 2, 0, 0, 1, 2, 3, 0, 0, 0, 1, 0, 1, 2, 3, 4, 0, 0, 0, 0, 1, 0, 1, 0, 1, 2, 0, 0, 1, 2, 3, 4, 5, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 3, 0, 0, 0, 1, 0, 1, 2, 3, 4, 5, 6, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 3, 0, 0, 0, 1, 0

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OFFSET

1,7

COMMENTS

For k > 1, apparently the smallest n such that a(n) = k is 2^k + k + 1 (see A005126).

LINKS

Table of n, a(n) for n=1..105.

PROG

(PARI) {m=105; w=vector(2*m); print1(1, ", "); for(n=2, m, k=n; while(w[k], k--); a=n+k; print1(2*n-a, ", "); w[a]=1)}

CROSSREFS

Cf. A123088, A005126.

Sequence in context: A301593 A089731 A097098 * A167948 A111755 A144528

Adjacent sequences: A123676 A123677 A123678 * A123680 A123681 A123682

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Oct 05 2006

STATUS

approved