login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A330303 Least start of a run of exactly n consecutive odd numbers that are all de Polignac numbers (A006285). 0
1, 905, 18895, 56287, 3296885, 53892169, 496722329, 1415354159, 110690012639 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

a(2) = 905 since both 905 and 905 + 2 = 907 are de Polignac numbers.

a(3) = 18895 since 18895, 18895 + 2 = 18897 and 18895 + 4 = 18899 are all de Polignac numbers.

MATHEMATICA

dePolQ[n_] := AllTrue[n - 2^Range[0, Floor[Log[2, n]]], !PrimeQ[#] &]; max = 5; seq = Table[0, {max}]; count = 0; k = 3; While[count < max, If[dePolQ[k], kk = k + 2; While[dePolQ[kk], kk += 2]; n = (kk - k)/2; If[n <= max && seq[[n]] == 0, count++; seq[[n]] = k]; k = kk + 2, k += 2]]; seq

CROSSREFS

Cf. A006285, A330284.

Sequence in context: A068856 A235949 A330284 * A181257 A235242 A270446

Adjacent sequences:  A330300 A330301 A330302 * A330304 A330305 A330306

KEYWORD

nonn,more

AUTHOR

Amiram Eldar, Dec 13 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 20 17:19 EST 2022. Contains 350472 sequences. (Running on oeis4.)