The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A177931 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A177931

Locations of records in A177930.
(history; published version)

#14 by Alois P. Heinz at Sat Feb 24 15:09:29 EST 2024

STATUS

proposed

approved

#13 by Michel Marcus at Sat Feb 24 13:01:30 EST 2024

STATUS

editing

proposed

#12 by Michel Marcus at Sat Feb 24 13:01:26 EST 2024

EXTENSIONS

More terms from Jean-François Alcover, Feb 24 2024

STATUS

proposed

editing

#11 by Jean-François Alcover at Sat Feb 24 12:59:05 EST 2024

STATUS

editing

proposed

#10 by Jean-François Alcover at Sat Feb 24 12:59:00 EST 2024

MATHEMATICA

Position[t = Table[b[n], {n, 1, 1000}], k_ /; PrimeQ[k-1] && PrimeQ[k+1]] // Flatten (* Jean-François Alcover, Feb 24 2024 *)

STATUS

proposed

editing

#9 by Jean-François Alcover at Sat Feb 24 12:58:00 EST 2024

STATUS

editing

proposed

#8 by Jean-François Alcover at Sat Feb 24 12:56:33 EST 2024

DATA

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, 1388, 1395, 1430, 1438, 1624, 1817, 2082, 2396, 2423, 2978, 3133, 3138, 3432, 3511, 3699, 3838, 4024, 4104, 4589, 4930

MATHEMATICA

lpf[n_] := FactorInteger[n][[1, 1]];

b[n_] := b[n] = If[n == 1, 4, b[n-1] + lpf[b[n-1]^2-1]-1];

Position[t = Table[b[n], {n, 1, 1000}], k_ /; PrimeQ[k-1] && PrimeQ[k+1]] // Flatten (* Jean-François Alcover, Feb 24 2024 *)

STATUS

approved

editing

#7 by Jon E. Schoenfield at Mon Feb 18 04:44:14 EST 2019

STATUS

proposed

approved

#6 by Jon E. Schoenfield at Mon Feb 18 04:44:10 EST 2019

STATUS

editing

proposed

#5 by Jon E. Schoenfield at Mon Feb 18 04:44:08 EST 2019

MAPLE

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

STATUS

approved

editing