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!)
A112376 Sum of base and exponent of prime powers. 1
3, 4, 4, 6, 8, 5, 5, 12, 14, 6, 18, 20, 24, 7, 6, 30, 32, 7, 38, 42, 44, 48, 9, 54, 60, 62, 8, 68, 72, 74, 80, 7, 84, 90, 98, 102, 104, 108, 110, 114, 13, 8, 128, 9, 132, 138, 140, 150, 152, 158, 164, 168, 15, 174, 180, 182, 192, 194, 198, 200, 212, 224, 228, 230, 234, 240, 242 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If n = p^q, where p is prime and q > 0, then p+q is in the sequence.

If n is not of that form, omit the term.

Might be a good "puzzle" sequence - guess the rule given the first ten or so terms.

LINKS

Table of n, a(n) for n=1..67.

EXAMPLE

n = 3 = 3^1, so 3+1 = 4 is a term; n = 4 = 2^2, so 2+2 = 4 is again a term; n = 5 = 5^1, so we get 5+1 =6.

But 6 is not a prime power, so we skip it.

PROG

(PARI) for(n=1, 300, fac=factor(n); if(matsize(fac)[1]==1, print1(fac[1, 1]+fac[1, 2], ", ")))

CROSSREFS

Cf. A112375, A064438.

A008474 is another version, defined for all n.

Sequence in context: A008474 A111611 A100478 * A161359 A224212 A078490

Adjacent sequences:  A112373 A112374 A112375 * A112377 A112378 A112379

KEYWORD

nonn

AUTHOR

Zak Seidov, Dec 04 2005

EXTENSIONS

Edited and extended by Klaus Brockhaus, Jan 21 2006

Further edited by N. J. A. Sloane, Nov 19 2018

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 May 29 20:42 EDT 2020. Contains 334710 sequences. (Running on oeis4.)