A189936 Odd numbers in A076763.

105, 165, 195, 255, 273, 315, 345, 357, 385, 399, 465, 483, 525, 555, 585, 627, 663, 693, 705, 735, 765, 777, 795, 897, 915, 957, 975, 1005, 1095, 1113, 1155, 1173, 1185, 1281, 1295, 1305, 1353, 1365, 1515, 1545, 1575, 1617, 1677, 1683, 1725, 1755, 1785, 1815, 1935, 1953

Offset: 1

Author

Juri-Stepan Gerasimov, May 01 2011

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A001221, A076763, A013590, A118678, A154430.

Programs

Maple

omega := proc(n) nops( numtheory[factorset](n)) ; end proc:
isA076763 := proc(n) omega(n) > omega(n-1) and omega(n) > omega(n+1) ; end proc:
isA189936 := proc(n) type(n,'odd') and isA076763(n) ; end proc:
for n from 1 to 2000 by 2 do if isA189936(n) then printf("%d,",n) ; end if; end do;  # R. J. Mathar, May 26 2011

Mathematica

Select[Range[1, 2000, 2], PrimeNu[# - 1] < PrimeNu[#] > PrimeNu[# + 1]&] (* Jean-François Alcover, Nov 14 2016 *)
Select[#[[2,1]]&/@Select[Partition[Table[{n,PrimeNu[n]},{n,2000}],3,1], #[[1,2]] <#[[2,2]]>#[[3,2]]&],OddQ] (* Harvey P. Dale, Sep 15 2019 *)

Formula

a(n) = A005408(k) = A076763(m).

Extensions

Corrected by R. J. Mathar, May 26 2011