A031884 -id:A031884 - cp's OEIS frontend

A031885 Lucky numbers with smallest increasing gaps (upper terms).

3, 7, 21, 87, 151, 63, 801, 511, 189, 957, 925, 769, 2877, 1639, 1087, 3843, 5803, 4929, 8757, 10723, 9883, 24117, 9613, 28293, 25737, 3559, 26997, 35799, 44863, 52039, 64785, 23269, 50845, 51543, 264145, 155905, 238131, 178831, 143389, 400671, 223177, 181665

Offset: 1

Patrick De Geest

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Cf. A000959, A031884.

a(27) corrected and more terms from Sean A. Irvine, May 03 2020

A118126 Lucky numbers (A000959) at which records in first differences (A031883) occur.

Original entry on oeis.org

1, 3, 15, 51, 171, 745, 1057, 3507, 23205, 50779, 51475, 97113, 241887, 593727, 636291, 1661215, 6010095, 6100953, 8825911, 22032619, 24058237, 71730273, 84577003, 98797723, 119871675, 255510487, 380154649, 404917765, 704823889, 910302427, 1696449051, 2565189555, 9024827079

Offset: 1

Robert G. Wilson v, May 12 2006

An increasing subset of sequence A031884.

			a(4) = 51 since the 4th record value in the lucky number "first differences" sequence occurs A031883(14) = 12 which corresponds to lucky number A000959(14) = 51.

Cf. A000959, A031883, A031884.

lst = Range[1, 10^6, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; lst2 = {}; d = 0; Do[a = t[[n + 1]] - t[[n]]; If[a > d, d = a; AppendTo[lst, t[[n]]]], {n, 5286237}]; lst2

a(25)-a(29) from Donovan Johnson, Oct 23 2010
a(30) from Donovan Johnson, Jun 20 2011
a(31)-a(33) from Kevin P. Thompson, Nov 24 2021

cp's OEIS Frontend

A031885 Lucky numbers with smallest increasing gaps (upper terms).

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A118126 Lucky numbers (A000959) at which records in first differences (A031883) occur.

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