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!)
A344694 Numbers k, not powers of primes, for which A011772(k) divides A344875(k), and for all proper divisors d of k, A011772(d) < A011772(k). 3
900, 1260, 1560, 3740, 6552, 6669, 9680, 18981, 19880, 35784, 36080, 59040, 62238, 62244, 81872, 103730, 108500, 118910, 134420, 160160, 171740, 185724, 211072, 217833, 222224, 225929, 227528, 259325, 351072, 384944, 404294, 414778, 422604, 425178, 446600, 456228, 463008, 488205, 490105, 527100, 574308, 581184, 598400 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Has many terms common with A344595.

LINKS

Table of n, a(n) for n=1..43.

PROG

(PARI)

A011772(n) = { if(n==1, return(1)); my(f=factor(if(n%2, n, 2*n)), step=vecmax(vector(#f~, i, f[i, 1]^f[i, 2]))); forstep(m=step, 2*n, step, if(m*(m-1)/2%n==0, return(m-1)); if(m*(m+1)/2%n==0, return(m))); }; \\ From A011772

A344875(n) = { my(f=factor(n)~); prod(i=1, #f, (f[1, i]^(f[2, i]+(2==f[1, i]))-1)); };

A344880(n) = { my(x=A011772(n)); fordiv(n, d, if(A011772(d)==x, return(d==n))); };

A344973(n) = (A344875(n)%A011772(n));

isA344694(n) = ((n>1)&&!isprimepower(n)&&(0==A344973(n))&&A344880(n));

CROSSREFS

Cf. A011772, A344880, A344973.

Intersection of A024619, A344881 and A344974. Intersection of A344881 and A344975.

Cf. also A344595, A344980.

Sequence in context: A158409 A061044 A344595 * A127658 A318720 A338540

Adjacent sequences:  A344689 A344690 A344693 * A344695 A344696 A344697

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jun 05 2021

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 July 27 07:36 EDT 2021. Contains 346304 sequences. (Running on oeis4.)