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 A202242 n such that the sum of digit !! of n equals the sum of d|n, 1
 14, 56, 28361, 119507, 191557, 287039, 691259, 750889 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS No further terms less than 10^8. The double factorial n!! (A006882) of a positive integer n is the product of the positive integers <= n that have the same parity as n. LINKS Table of n, a(n) for n=1..8. EXAMPLE 56 is in the sequence because 5!! + 6!! = 15 + 48 = 63, and sum of the divisors 1< d< 56 = sigma(56) - 56 - 1 = 120 - 56 - 1 = 63. MATHEMATICA Q[n_]:=Module[{a=Total[Rest[Most[Divisors[n]]]]}, a == Total[IntegerDigits[n]!!]]; Select[Range[2, 10^5], Q] CROSSREFS Cf. A006882, A048050. Sequence in context: A281200 A212341 A067326 * A041374 A070741 A022286 Adjacent sequences: A202239 A202240 A202241 * A202243 A202244 A202245 KEYWORD nonn,hard,base AUTHOR Michel Lagneau, Dec 16 2011 STATUS approved

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Last modified February 23 14:24 EST 2024. Contains 370283 sequences. (Running on oeis4.)