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A048572
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a(n) = sum of digits of a(n-1)*a(n-2).
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1
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1, 2, 2, 4, 8, 5, 4, 2, 8, 7, 11, 14, 10, 5, 5, 7, 8, 11, 16, 14, 8, 4, 5, 2, 1, 2, 2, 4, 8, 5, 4, 2, 8, 7, 11, 14, 10, 5, 5, 7, 8, 11, 16, 14, 8, 4, 5, 2, 1, 2, 2, 4, 8, 5, 4, 2, 8, 7, 11, 14, 10, 5, 5, 7, 8, 11, 16, 14, 8, 4, 5, 2
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| This sequence is periodic with period 24. - T. D. Noe (noe(AT)sspectra.com), Feb 15 2008
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FORMULA
| a(n)=(1/6624)*{439*(n mod 24)+991*[(n+1) mod 24]-113*[(n+2) mod 24]+1267*[(n+3) mod 24]+1819*[(n+4) mod 24]+715*[(n+5) mod 24]-1217*[(n+6) mod 24]-665*[(n+7) mod 24]-113*[(n+8) mod 24]-389*[(n+9) mod 24]+163*[(n+10) mod 24]+1543*[(n+11) mod 24]+1267*[(n+12) mod 24]-665*[(n+13) mod 24]-941*[(n+14) mod 24]+439*[(n+15) mod 24]-1493*[(n+16) mod 24]+715*[(n+17) mod 24]+439*[(n+18) mod 24]+991*[(n+19) mod 24]-941*[(n+20) mod 24]-389*[(n+21) mod 24]+163*[(n+22) mod 24]-113*[(n+23) mod 24]}, with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Apr 01 2009]
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MATHEMATICA
| Nest[Append[#, Total[IntegerDigits[Last[#]#[[-2]]]]]&, {1, 2}, 80] (* From Harvey P. Dale, Apr 21 2011 *)
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CROSSREFS
| Sequence in context: A077964 A077968 A123958 * A121173 A160159 A101651
Adjacent sequences: A048569 A048570 A048571 * A048573 A048574 A048575
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KEYWORD
| nonn,easy,nice,base
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AUTHOR
| David Johnson-Davies (david(AT)interface.co.uk)
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