login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093488 Define the signature symmetry of a number n to be k if n-r and n+r have the same prime signature for r = 1 to k but not for k+1. Sequence contains the signature symmetry of n. 5
0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,12

COMMENTS

Subsidiary sequence: Index of the first occurrence of n in this sequence.

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

a(12) = 2 as 11 and 13 are both prime 10 and 14 both have prime signature p*q but 9 and 15 have distinct prime signature.

CROSSREFS

Cf. A093489, A093491, A093492.

Sequence in context: A252459 A083918 A083895 * A085858 A188172 A106671

Adjacent sequences:  A093485 A093486 A093487 * A093489 A093490 A093491

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Apr 16 2004

EXTENSIONS

More terms from Joshua Zucker, Jul 24 2006

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 October 20 14:24 EDT 2021. Contains 348108 sequences. (Running on oeis4.)