|
|
A112375
|
|
Concatenation of base and exponent of prime powers.
|
|
3
|
|
|
21, 31, 22, 51, 71, 23, 32, 111, 131, 24, 171, 191, 231, 52, 33, 291, 311, 25, 371, 411, 431, 471, 72, 531, 591, 611, 26, 671, 711, 731, 791, 34, 831, 891, 971, 1011, 1031, 1071, 1091, 1131, 112, 53, 1271, 27, 1311, 1371, 1391, 1491, 1511, 1571, 1631, 1671
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
If n = p^q, where p is prime and q > 0, then p concatenated with q is in the sequence.
Might be a good "puzzle" sequence - guess the rule given the first ten or so terms.
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
n = 3 = 3^1, so (3 concatenated with 1) = 31 is a term.
|
|
MATHEMATICA
|
Map[FromDigits, Select[Table[FactorInteger[i], {i, 2, 10000}],
|
|
PROG
|
(PARI) for(n=1, 300, fac=factor(n); if(matsize(fac)[1]==1, print1(eval(concat(Str(fac[1, 1]), Str(fac[1, 2]))), ", ")))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|