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!)
A154779 Number of terms with n digits in A154780. 1
1, 1, 2, 2, 4, 6, 12, 17, 34, 55, 98, 161, 288, 448, 811, 1265, 2145, 3425, 5860, 9305, 15384, 24690, 40445, 64715 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Does the ratio of consecutive terms, a(n+1)/a(n), tend to a finite limit?

LINKS

Table of n, a(n) for n=1..24.

PROG

(PARI) print1("1, ", #last=[35]); for(d=3, 30, new=[]; forprime( p=0, 9, for(k=1, #last, isprime((last[k]^2\10^d+t*last[k]/5)%10) & new=concat(new, last[k]+p*10^(d-1)))); print1(", ", #last=new))

CROSSREFS

Sequence in context: A228892 A267610 A291365 * A332983 A010101 A274942

Adjacent sequences:  A154776 A154777 A154778 * A154780 A154781 A154782

KEYWORD

nonn,base

AUTHOR

M. F. Hasler, Jan 24 2009

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 June 1 18:43 EDT 2020. Contains 334762 sequences. (Running on oeis4.)