A334950 -id:A334950 - cp's OEIS frontend

A334952 First differences of A334950.

0, -1, 2, -2, 4, -3, 6, -4, 0, -5, 10, -6, 12, -7, 14, -8, 0, -9, 18, -10, 0, -11, 22, -12, 0, -13, 26, -14, 0, -15, 30, -16, 0, -17, 34, -18, 36, -19, 38, -20, 0, -21, 42, -22, 0, -23, 0, -24, 48, -25, 0, -26, 52, -27, 0, -28, 56, -29, 0, -30, 60, -31, 0, -32, 64, -33, 66, -34, 68, -35, 0, -36, 72, -37

Offset: 0

Omar E. Pol, May 17 2020

sign

The absolute value of a(n) is also the length of the n-th vertical-line-segment in the diagram of A334950.

Index entries for sequences related to Recamán's sequence

Cf. A001478, A005132, A334950, A334951.

a(2k+1) = -(k + 1), k >= 0.

A334951 a(n) is the smallest candidate for the n-th term of Recamán's sequence A005132.

Original entry on oeis.org

0, -1, -1, 0, 2, -3, 1, 6, 12, 3, 11, 0, 10, -3, 9, -6, 8, -9, 7, 24, 42, 21, 41, 18, -6, 17, -9, 16, -12, 15, -15, 14, -18, 13, 45, 78, 42, 77, 39, 0, 38, -3, 37, -6, 36, -9, 35, -12, 34, -15, 33, -18, 32, -21, 31, -24, 30, -27, 29, -30, 28, -33, 27, -36, 26, -39, 25, 90, 156, 87, 155, 84

Offset: 0

Omar E. Pol, May 17 2020

sign

For n > 0 and after A005132(n-1) the algorithm of Recamán's sequence first explores if a(n) is a valid number to be its next term. If a(n) is nonnegative and not already in the sequence A005132 then a(n) is accepted, so A005132(n) = a(n), otherwise a(n) is rejected and A005132(n) = A005132(n-1) + n, not a(n).

For an illustration of initial terms see the diagram in A334950.

Rémy Sigrist, Table of n, a(n) for n = 0..10000
Index entries for sequences related to Recamán's sequence

Bisection of A334950.

Cf. A005132, A334952.

a(0) = 0; for n > 0, a(n) = A005132(n-1) - n.

cp's OEIS Frontend

A334952 First differences of A334950.

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