

A076406


Numbers whose digital sum is equal to the sum of primes from their smallest to largest prime factor.


1



2, 3, 5, 7, 98, 640, 735, 980, 2401, 2625, 2744, 4913, 5145, 6272, 6400, 9800, 9856, 14336, 27440, 33614, 36015, 58564, 62720, 64000, 94325, 98000, 98560, 143360, 188650, 232925, 252105, 274400, 298144, 336140, 401408, 405769, 465850, 570999
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OFFSET

1,1


LINKS

Donovan Johnson, Table of n, a(n) for n = 1..500


EXAMPLE

980 = 2*2*5*7*7 is here since 9+8 = 17 and 2+3+5+7 = 17.


MATHEMATICA

okQ[n_]:=Module[{totidn=Total[ IntegerDigits[n]], fctrs, mn, mx}, fctrs= Transpose[FactorInteger[n]][[1]]; mn=Min[fctrs]; mx=Max[fctrs]; Total[Prime[Range[PrimePi[mn], PrimePi[mx]]]]==totidn];
Select[ Range[2, 10000], okQ] (* Harvey P. Dale *)


CROSSREFS

Sequence in context: A068827 A289755 A318202 * A171050 A092909 A080437
Adjacent sequences: A076403 A076404 A076405 * A076407 A076408 A076409


KEYWORD

base,nonn


AUTHOR

Jason Earls, Nov 07 2002


EXTENSIONS

a(20)a(38) from Donovan Johnson, Sep 24 2009


STATUS

approved



