OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..7500
EXAMPLE
MAPLE
N:= 5*10^5: # for terms <= N
dcat:= proc(L) local i, x;
x:= L[-1];
for i from nops(L)-1 to 1 by -1 do
x:= 10^(1+ilog10(x))*L[i]+x
od;
x
end proc:
A037276:= proc(n) local F;
F:= sort(ifactors(n)[2], (a, b) -> a[1] < b[1]);
dcat(map(t -> t[1]$t[2], F));
end proc:
A037276(1):= 1:
R:= NULL:
for n from 1 to N/2 do
v:= n + A037276(n);
if v < N and isprime(v) then R:= R, v fi;
od:
S:= {R}:
select(s -> numboccur(s, [R])>1, S);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
J. M. Bergot and Robert Israel, Jan 14 2021
STATUS
approved