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!)
A138818 Concatenation of initial digit of n-th even superperfect number A061652(n), initial digit of n-th Mersenne prime A000668(n) and initial digit of n-th perfect number A000396(n). 5
236, 472, 134, 618, 483, 618, 251, 122, 122, 361, 811, 811 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Also, concatenation of initial digit of n-th superperfect number A019279(n), initial digit of n-th Mersenne prime A000668(n) and initial digit of n-th perfect number A000396(n), if there are no odd superperfect numbers.

Also, concatenation of A138124(n), A135613(n) and A135617(n).

LINKS

Table of n, a(n) for n=1..12.

L. C. Noll, Mersenne Prime Digits and Names.

J. M. Pedersen, Known Perfect Numbers.

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.

CROSSREFS

Cf. A000396, A000668, A019279, A061652, A135613, A135617, A138124, A138816, A138817, A138819, A138841, A138842, A138843.

Sequence in context: A244007 A218054 A235286 * A138819 A273181 A259639

Adjacent sequences:  A138815 A138816 A138817 * A138819 A138820 A138821

KEYWORD

base,more,nonn,less

AUTHOR

Omar E. Pol, Apr 05 2008

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 22:22 EDT 2021. Contains 348119 sequences. (Running on oeis4.)