OFFSET
0,2
COMMENTS
FORMULA
SOD's are calculated for these indices; if they and their associated prime SOD's are both prime and bear the relation in the Brief description above, they are added to the sequence.
EXAMPLE
a(4) = 30. Its associated prime is 113 with sod = 5; sod(a(4)) = 3. Since 3 < 5 and 5 is the next prime after 3, a(4) belongs in the sequence.
PROG
(UBASIC)
10 'use of str, mid, len, val
20 'in SOD prime index and SOD prime
30 Y=1
40 Y=nxtprm(Y)
50 C=C+1:print C; Y; "-";
60 D=str(C):Z=str(Y)
70 E=len(D):F=len(Z)
80 for Q=2 to E
90 A=mid(D, Q, 1):G=val(A)
100 I=I+G:print I;
110 next Q
120 for R=2 to F
130 B=mid(Z, R, 1):H=val(B)
140 J=J+H:print J;
150 next R
160 if I=prmdiv(I) and J=prmdiv(J) and I<J and J=nxtprm(I) then stop
170 I=0:J=0
180 goto 40
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Enoch Haga, Mar 18 2006
STATUS
approved