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 A175811 A007318-deficient numbers. 6
 1, 7, 11, 13, 17, 18, 19, 23, 24, 25, 29, 30, 31, 32, 33, 37, 38, 39, 40, 41, 42, 43, 47, 48, 49, 50, 51, 52, 53, 57, 58, 59, 60, 61, 62, 63, 67, 68, 69, 70, 71, 72, 73, 74, 75, 79, 81, 82, 83, 84, 85, 86, 87, 88, 89, 93, 94, 95, 96, 97, 98, 99, 100, 101, 103, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Definition see in comment to A175522. The same criticism on index-selection as in A175807 applies. All primes greater than 5 are in the sequence. LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 FORMULA {n: sum_{d|n, d n then return binomial(r, n-t) ; end if; t := t+r+1 ; end do: end proc: isA175811 := proc(n) m := 0 ; for d in numtheory[divisors](n) minus {n} do m := m+A007318(d) ; end do; m < A007318(n) ; end proc: for n from 1 to 120 do if isA175811(n) then printf("%d, ", n); end if; end do: # R. J. Mathar, Dec 06 2010 PROG (PARI) b(n) = {my(m = 1); while (m*(m+1)/2 < n, m++); if (! ispolygonal(n, 3), m--); binomial(m, n - m*(m+1)/2); } isok(n) = sumdiv(n, d, (d25 from R. J. Mathar, Dec 06 2010 STATUS approved

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Last modified July 25 12:05 EDT 2021. Contains 346289 sequences. (Running on oeis4.)