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A285098 Row sums of irregular triangle A070168. 2
1, 3, 23, 7, 20, 29, 124, 15, 147, 30, 117, 41, 63, 138, 296, 31, 106, 165, 231, 50, 84, 139, 281, 65, 294, 89, 40616, 166, 212, 326, 40486, 63, 377, 140, 258, 201, 259, 269, 986, 90, 40589, 126, 588, 183, 253, 327, 40455, 113, 382, 344, 514, 141, 223, 40670, 41000, 222 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) is the sum of numbers in trajectory of Terras-modified Collatz problem with first number n.

LINKS

Indranil Ghosh, Table of n, a(n) for n = 1..10000

EXAMPLE

The 5th row of irregular triangle A070168 is [5, 8, 4, 2, 1] whose sum is 20. a(5) = 5 + 8 + 4 + 2 + 1 = 20.

MATHEMATICA

a[n_]:=If[n<2, 1, If[OddQ[n], (3n + 1)/2, n/2]]; Table[-1 + Plus @@ FixedPointList[a, n], {n, 100}]

PROG

(Python)

def a(n):

    if n==1: return 1

    l=[n, ]

    while True:

        if n%2==0: n/=2

        else: n = (3*n + 1)/2

        l+=[n, ]

        if n<2: break

    return sum(l)

print [a(n) for n in xrange(1, 101)]

CROSSREFS

Cf. A033493, A070168.

Sequence in context: A105433 A196086 A196083 * A088605 A272816 A063562

Adjacent sequences:  A285095 A285096 A285097 * A285099 A285100 A285101

KEYWORD

nonn

AUTHOR

Indranil Ghosh, Apr 17 2017

STATUS

approved

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Last modified July 19 09:33 EDT 2019. Contains 325155 sequences. (Running on oeis4.)