|
Search: id:A107698
|
|
|
| A107698 |
|
Smallest prime whose digital product = n or 0 if impossible. |
|
+0
11
|
|
| 11, 2, 3, 41, 5, 23, 7, 181, 19, 251, 0, 43, 0, 127, 53, 281, 0, 29, 0, 541, 37, 0, 0, 83, 11551, 0, 139, 47, 0, 523, 0, 1481, 0, 0, 157, 149, 0, 0, 0, 12451, 0, 67, 0, 0, 59, 0, 0, 283, 11177, 2551, 0, 0, 0, 239, 0, 1187, 0, 0, 0, 1453, 0, 0, 79, 881, 0, 0, 0, 0, 0, 257, 0
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Zeros appear at A068191.
|
|
EXAMPLE
|
a(20)=541 because 5*4*1=20 and there is no prime less than a(20) which
exhibits this characteristic.
|
|
MATHEMATICA
|
f[n_] := If[ Max[ First /@ FactorInteger[n]] > 7, 0, p = 1; While[Times @@ IntegerDigits[ Prime[p]] != n, p++ ]; Prime[p]]; Table[ f[n], {n, 30}]
|
|
CROSSREFS
|
Cf. A004022, A107612, A107689, A107690, A107691, A107692, A107693, A107694, A107695, A107696, A107697.
Sequence in context: A099756 A088277 A089744 this_sequence A068164 A089754 A110743
Adjacent sequences: A107695 A107696 A107697 this_sequence A107699 A107700 A107701
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
Zak Seidov (zakseidov(AT)yahoo.com) and Robert G. Wilson v (rgwv(AT)rgwv.com), May 20 2005
|
|
|
Search completed in 0.002 seconds
|
