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A177512 A053735-deficient numbers. 1
1, 2, 5, 7, 11, 13, 17, 19, 23, 25, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 121, 127, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For definition, see A175522.

All primes, except for 3, are in the sequence.

It also contains squared primes p^2 for p = 5, 7, 11, 13, 19, 23, 29, 31, 37.. (not matching current OEIS sequences). What characterizes these p?

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

{n: sum_{d|n, d<n} A053735(d) < A053735(n)}.

PROG

(Sage) is_A177512 = lambda n: sum(A053735(d) for d in divisors(n)) < 2*A053735(n) # D. S. McNeil, Dec 11 2010

(PARI) isok(n) = sumdiv(n, d, (d<n)* vecsum(digits(d, 3))) < vecsum(digits(n, 3)); \\ Michel Marcus, Feb 06 2016

CROSSREFS

Cf. A177511 (perfect version), A175524, A175811, A000040, A005100, A005101.

Sequence in context: A157829 A020581 A081259 * A118751 A173494 A137519

Adjacent sequences:  A177509 A177510 A177511 * A177513 A177514 A177515

KEYWORD

nonn,base

AUTHOR

Vladimir Shevelev, Dec 11 2010

STATUS

approved

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Last modified May 16 18:13 EDT 2021. Contains 343949 sequences. (Running on oeis4.)