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A101634
Subtract 1, multiply by 1, subtract 2, multiply by 2, etc.
0
6, 5, 6, 9, 20, 75, 414, 2849, 22728, 204471, 2044610, 22490589, 269886924, 3508529843, 49119417606, 736791263865, 11788660221584, 200407223766639, 3607330027799178, 68539270528184021, 1370785410563680020
OFFSET
1,1
COMMENTS
Inspired by A019460. a(1) = 6 is the least integer producing all nonnegative terms.
FORMULA
Recurrence: a(1) = 6; a(n+1) = n*a(n) - n^2. [Edited by Georg Fischer, Dec 28 2021]
MATHEMATICA
a=6; bb={a}; Do[b=i(a-i); a=b; bb={bb, a}, {i, 20}]; Flatten[bb]
CROSSREFS
Cf. A019460.
Sequence in context: A335263 A126689 A243093 * A071176 A243091 A195786
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Jan 26 2005
STATUS
approved