A294995 - OEIS

A294995

Numbers n such that sopfr(n) = sopfr(n-1) + sopfr(n-2), where sopfr is the sum of prime factors of n with multiplicity (A001414).

23, 610, 1162, 1243, 1651, 7385, 13066, 37129, 38123, 41194, 41361, 48511, 59452, 72179, 83151, 87375, 98877, 103528, 126497, 138190, 141037, 148657, 157994, 162410, 175077, 262788, 296482, 299398, 351226, 354321, 418134, 425099, 452130, 465254, 470494

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..1179

EXAMPLE

610 is in the sequence since sopfr(608) = 29, sopfr(609) = 39 and sopfr(610) = 68 = 39 + 29.

MATHEMATICA

f[n_]:=Plus @@ Times @@@ FactorInteger@ n; Select[Range[10^5], f[#]==f[#-1]+f[#-2] &]

PROG

(PARI) sopfr(n, f=factor(n))=f[, 1]~*f[, 2]

list(lim)=my(v=List(), a=0, b=2, c); forfactored(k=3, lim\1, c=sopfr(k[2]); if(c==a+b, listput(v, k[1])); a=b; b=c); Vec(v) \\ Charles R Greathouse IV, Nov 12 2017

CROSSREFS

Cf. A001414, A075565.

Sequence in context: A106538 A203102 A362482 * A142750 A202667 A129991

Adjacent sequences: A294992 A294993 A294994 * A294996 A294997 A294998

KEYWORD

nonn

AUTHOR

Amiram Eldar, Nov 12 2017

STATUS

approved