OFFSET
1,1
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
Seen as an irregular triangle T(n,k) of rows n where T(n,k) = P(n)*k, and k < prime(n+1) is in A369361.
n\k 3 5 7 9 10 11
------------------------------------------------
2: 18;
3: 90, 150;
4: 630, 1050, 1470, 1890, 2100;
5: 6930, 11550, 16170, 20790, 23100, 25410;
...
MATHEMATICA
P = 2; nn = 8;
s = Select[Range[3, Prime[nn+1]],
Nor[IntegerQ@ Log2[#],
And[EvenQ[#1], Union@ Differences@ PrimePi[#2[[All, 1]]] == {1},
AllTrue[Differences@ #2[[All, -1]], # <= 0 &]]] & @@
{#, FactorInteger[#]} &];
Table[P *= Prime[n]; P*TakeWhile[s, # < Prime[n + 1] &], {n, 2, nn}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael De Vlieger, Mar 10 2024
STATUS
approved