A309672 Composite terms of A007755.

2329, 4369, 10537, 35209, 281929, 1114129, 8978569, 16843009, 143163649, 286331153, 1086374209, 4295098369, 9198250129, 18325194049, 36507844609, 73016672273, 139055899009, 277033877569, 586397253889, 1103840280833, 4673067091009, 9382516064513, 17868687216769

Offset

1,1

Comments

10537 is a term because it is composite (= 41*257) and the totient (A000010) iterating "trajectory" starting from 10537 and ending in 1 is longer (length 15) than any similar trajectory starting from a (prime or nonprime) N < 10537.

Links

Table of n, a(n) for n=1..23.

Crossrefs

Cf. A000010, A003434, A049108, A007755, A098196.

Sequence in context: A355420 A232107 A186058 * A238175 A203344 A178552

Adjacent sequences: A309669 A309670 A309671 * A309673 A309674 A309675

Keyword

nonn

Author

Jeppe Stig Nielsen, Oct 05 2019

Status

approved