A214548 - OEIS

A214548

List of k such that A214686(k) = 1.

2, 3, 5, 7, 9, 11, 17, 25, 33, 35, 37, 39, 43, 45, 51, 57, 61, 63, 65, 69, 71, 73, 77, 79, 85, 91, 97, 103, 105, 109, 115, 121, 123, 127, 129, 137, 141, 153, 167, 171, 177, 179, 183, 185, 193, 199, 211, 213, 221, 225, 229, 235, 241, 245, 249, 255, 259, 261

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OFFSET

1,1

COMMENTS

It seems that a(n) = 1 + floor(sqrt(A214686(a(n)+1))) which complies with an observation of Robert Israel.

LINKS

Table of n, a(n) for n=1..58.

Robert Israel, A214686

PROG

(Sage)

def A214548_list(n) : # n is a search limit

a = []; r = 1; f = 1

for k in (1..n) :

f = f * k

if k-1 == gcd(r-1, f) :

a.append(k); t = 1

else :

for t in range(r-1, -1, -1) :

if gcd(t, f) == 1 : break

r = (k+1)*(r-t)

return a

A214548_list(261)

CROSSREFS

Sequence in context: A066824 A036963 A120431 * A254440 A284914 A293262

Adjacent sequences: A214545 A214546 A214547 * A214549 A214550 A214551

KEYWORD

nonn,changed

AUTHOR

Peter Luschny, Jul 28 2012

STATUS

approved