A364543 Odd numbers k for which A005940(k) <= k.

1, 3, 5, 9, 17, 33, 35, 65, 67, 69, 129, 131, 133, 135, 137, 257, 259, 261, 263, 265, 267, 273, 289, 385, 513, 515, 517, 519, 521, 523, 525, 527, 529, 531, 545, 577, 641, 769, 1025, 1027, 1029, 1031, 1033, 1035, 1037, 1039, 1041, 1043, 1045, 1047, 1057, 1059, 1089, 1091, 1153, 1281, 1537, 2049, 2051, 2053, 2055

Offset: 1

Author

Antti Karttunen, Aug 06 2023

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..11023; terms less than 2^23

Crossrefs

Odd terms of A364541.

Cf. A005940, A364563 [= -A364499(a(n))].

Subsequences: A364547, A364573.

Cf. also A364293.

Programs

PARI

A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t };
isA364543(n) = ((n%2)&&(A005940(n)<=n));