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A177931 Locations of records in A177930. 4
1, 2, 4, 8, 10, 16, 20, 24, 29, 33, 36, 46, 76, 99, 108, 132, 179, 213, 217, 251, 286, 397, 431, 439, 445, 471, 535, 658, 677, 702, 780, 889, 1227, 1296 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Or: positions m for which A177929(m)-1 and A177929(m)+1 are twin primes.

LINKS

Table of n, a(n) for n=1..34.

MAPLE

A020639 := proc(n) numtheory[factorset](n) ; min(op(%)) ; end proc:

A177929 := proc(n) option remember; if n = 1 then 4; else d1 := A020639(procname(n-1)-1) ; d2 := A020639(procname(n-1)+1) ; procname(n-1)+min(d1, d2) -1; end if; end proc:

A177930 := proc(n) d1 := A020639(A177929(n)-1) ; d2 := A020639(A177929(n)+1) ; min(d1, d2) ; end proc:

read("transforms") ; L := [seq(A177930(n), n=1..1300)] ; RECORDS(L)[2] ; # R. J. Mathar, May 31 2010

CROSSREFS

Cf. A177929, A177930, A001359, A174514, A174216, A174217.

Sequence in context: A032533 A062884 A026169 * A060378 A185064 A036975

Adjacent sequences: A177928 A177929 A177930 * A177932 A177933 A177934

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, May 15 2010

EXTENSIONS

Extended by R. J. Mathar, May 31 2010

STATUS

approved

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Last modified January 27 02:41 EST 2023. Contains 359836 sequences. (Running on oeis4.)