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.

Showing 1-2 of 2 results.

A031884 Smaller of a pair of consecutive lucky numbers with a gap of 2n.

Original entry on oeis.org

1, 3, 15, 79, 141, 51, 787, 495, 171, 937, 903, 745, 2851, 1611, 1057, 3811, 5769, 4893, 8719, 10683, 9841, 24073, 9567, 28245, 25687, 3507, 26943, 35743, 44805, 51979, 64723, 23205, 50779, 51475, 264075, 155833, 238057, 178755, 143311, 400591, 223095, 181581, 466813
Offset: 1

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Comments

a(n) is the first occurrence of a difference of 2n between A000959(k+1) and A000959(k). - Robert G. Wilson v, May 12 2006
a(136) > 10^9. - Donovan Johnson, Dec 07 2011
Unknown terms a(166), a(176), a(178), a(182), and a(185) through a(209) are all greater than 10^10. - Kevin P. Thompson, Nov 24 2021

Examples

			a(4) = 79 since the lucky numbers A000959(20) = 79 and A000959(21) = 87 are the first consecutive pair with difference 2*4 = 8.
		

Crossrefs

Programs

  • Mathematica
    lst = Range[1, 10^6, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; f[n_] := Block[{k = 1}, While[t[[k + 1]] - t[[k]] != 2n, k++ ]; t[[k]]]; Array[f, 41] (* Robert G. Wilson v, May 12 2006 *)

Extensions

More terms from Robert G. Wilson v, May 12 2006

A031899 Lucky numbers with size of gaps equal to 16 (upper terms).

Original entry on oeis.org

511, 1417, 1435, 1519, 1765, 1915, 2395, 2461, 3091, 3259, 3427, 3595, 3811, 3865, 3931, 4285, 4645, 4741, 5449, 6211, 6463, 7231, 7435, 7549, 8191, 8347, 8977, 9331, 10111, 10255, 10459, 10525, 10651, 10747, 11113, 11599, 11659
Offset: 1

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Showing 1-2 of 2 results.