A338071 Values of w(k) when w(k-2), w(k-1), and w(k) are all odd, where w is A336957.

3263, 7183, 11671, 16291, 16601, 20741, 23257, 28639, 37667, 33163, 38819, 43849, 51469, 52789, 48701, 50275, 63323, 65117, 67903, 67223, 79751, 72193, 71265, 79183, 80743, 74741, 106483, 90571, 94159, 104467, 108043, 135821, 109771, 112561, 119149, 149387, 116377, 137951

Offset

1,1

Comments

See comments in A337644.

It would be nice to understand what is special about these numbers. The majority of them appear to products of two distinct primes. There seems to be very little overlap with either A337646 or A338057, although 1531513 appears both here and in A337646.

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..575

Example

The factorizations of the first 10 terms are:
1, (13)*(251)
2, (11)*(653)
3, (11)*(1061)
4, (11)*(1481)
5, (13)*(1277)
6, (7)*(2963)
7, (13)*(1789)
8, (13)*(2203)
9, (7)*(5381)
10, (13)*(2551)
The factorizations of terms 555 through 575 are:
555, (11)*(118681)
556, (7)*(213833)
557, (7)*(213887)
558, (11)*(118901)
559, (3)*(5)*(83059)
560, (11)*(120619)
561, (13)*(98867)
562, (11)*(121021)
563, (13)*(99391)
564, (7)*(218873)
565, (11)*(121621)
566, (13)*(99571)
567, (13)*(99989)
568, (11)*(122299)
569, (13)*(122503)
570, (11)*(122533)
571, (11)*(122579)
572, (13)*(100537)
573, (7)*(221537)
574, (11)*(123427)
575, (31)*(38393)

Crossrefs

Cf. A336957, A337644, A337646, A338057, A338070.

Sequence in context: A135134 A137836 A251919 * A234653 A254492 A254485

Adjacent sequences: A338068 A338069 A338070 * A338072 A338073 A338074

Keyword

nonn

Author

N. J. A. Sloane, Oct 19 2020

Status

approved