login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A112375 Concatenation of base and exponent of prime powers. 2
21, 31, 22, 51, 71, 23, 32, 111, 131, 24, 171, 191, 231, 52, 33, 291, 311, 25, 371, 411, 431, 471, 72, 531, 591, 611, 26, 671, 711, 731, 791, 34, 831, 891, 971, 1011, 1031, 1071, 1091, 1131, 112, 53, 1271, 27, 1311, 1371, 1391, 1491, 1511, 1571, 1631, 1671 (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 concatenated with q is in the sequence.

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..52.

FORMULA

a(n) = A067599(A246655(n)) = A067599(A000961(n+1)). - M. F. Hasler, Mar 14 2018

EXAMPLE

n = 3 = 3^1, so (3 concatenated with 1) = 31 is a term.

PROG

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

CROSSREFS

Cf. A112376, A064438, A067599.

Sequence in context: A116096 A116116 A079394 * A067599 A261322 A123846

Adjacent sequences:  A112372 A112373 A112374 * A112376 A112377 A112378

KEYWORD

nonn,base

AUTHOR

Zak Seidov, Dec 04 2005

EXTENSIONS

Edited and extended by Klaus Brockhaus, Jan 21 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 November 17 13:33 EST 2019. Contains 329230 sequences. (Running on oeis4.)