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A117084
Octagonal numbers for which both the sum and the product of the digits is also an octagonal number.
0
0, 1, 8, 1160, 20501, 30401, 42960, 90480, 131880, 168033, 181056, 208560, 238008, 269400, 302736, 338016, 375240, 414408, 455520, 520833, 590520, 690240, 743016, 770133, 854400, 913008, 943041, 1004565, 1036056, 1068033, 1100496, 1235208
OFFSET
0,3
EXAMPLE
42960 is in the sequence because (1) it is an octagonal number, the sum of its digits 4+2+9+6+0 = 21 is an octagonal number and (3) the product of its digits 4*2*9*6*0 = 0 is also an octagonal number.
CROSSREFS
Cf. A000567.
Sequence in context: A357543 A003767 A221084 * A201985 A301614 A180767
KEYWORD
base,nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), Apr 17 2006
STATUS
approved