A045959 Numbers k in A045954 such that k-1 is prime.
4, 6, 12, 18, 20, 42, 44, 54, 68, 84, 90, 98, 102, 108, 114, 132, 138, 140, 150, 164, 182, 198, 212, 228, 230, 234, 278, 282, 308, 314, 332, 354, 374, 390, 420, 434, 458, 522, 524, 548, 570, 578, 588, 602, 614, 642, 644, 660, 674, 684, 710, 740, 822, 882, 884, 938, 954
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
-
Mathematica
seq[max_] := Module[{lst = Range[2, max, 2], i = 2, len}, While[i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++]; Select[lst, PrimeQ[# - 1] &]]; seq[1000] (* Amiram Eldar, Mar 20 2024, after Robert G. Wilson v at A045954 *)
Extensions
Title corrected by Sean A. Irvine, Mar 29 2021