A317743 - OEIS

A317743

Valleys in A064800: terms which are smaller than their neighbors.

14, 18, 20, 27, 30, 32, 35, 38, 42, 44, 51, 54, 57, 59, 62, 67, 68, 72, 74, 80, 87, 90, 93, 98, 102, 104, 110, 114, 123, 128, 131, 132, 135, 138, 140, 143, 147, 150, 152, 158, 163, 164, 171, 174, 179, 182, 187, 192, 194, 198, 200

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

From Zak Seidov, Sep 21 2018: (Start)

First second-order valley is a(514) = 516

with {521, 517, 516, 517, 520}.

First third-order valley is a(k=265827) = 265829

with {265833, 265831, 265830, 265829, 265831, 265832, 265834}.

Are there minima of higher order? (End)

LINKS

Table of n, a(n) for n=1..51.

EXAMPLE

a(1) = 14 is the first valley (local minimum) in A064800 as A064800(13) = 14 is less than A064800(12) = 15 and A064800(14) = 16.

MATHEMATICA

Transpose[ Select[ Partition[(# + PrimeOmega[#]) & /@ Range[201], 3, 1], #[[1]] > #[[2]] < #[[3]] &]][[2]] (* Giovanni Resta, Aug 09 2018 *)

PROG

(PARI) lista(nn) = {my(v = vector(nn, n, n + bigomega(n))); for (n=2, nn, if ((v[n] < v[n-1]) && (v[n] < v[n+1]), print1(v[n], ", ")); ); } \\ Michel Marcus, Sep 07 2018

CROSSREFS

Cf. A064800, A319504.

Sequence in context: A365792 A060504 A052026 * A118499 A111205 A097324

Adjacent sequences: A317740 A317741 A317742 * A317744 A317745 A317746

KEYWORD

nonn

AUTHOR

Zak Seidov, Aug 05 2018

STATUS

approved